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M. I. Faley
Peter Grünberg Institute 5, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

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Journal article
Published: 12 February 2021 in Nanomaterials
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Nanobridge Josephson junctions and nanometer-scale superconducting quantum interference devices (nanoSQUIDs) based on titanium nitride (TiN) thin films are described. The TiN films have a room temperature resistivity of ~15 µΩ·cm, a superconducting transition temperature Tc of up to 5.3 K and a coherence length ξ(4.2 K) of ~105 nm. They were deposited using pulsed DC magnetron sputtering from a stoichiometric TiN target onto Si (100) substrates that were heated to 800 °C. Electron beam lithography and highly selective reactive ion etching were used to fabricate nanoSQUIDs with 20-nm-wide nanobridge Josephson junctions of variable thickness. X-ray and high-resolution electron microscopy studies were performed. Non-hysteretic I(V) characteristics of the nanobridges and nanoSQUIDs, as well as peak-to-peak modulations of up to 17 µV in the V(B) characteristics of the nanoSQUIDs, were measured at 4.2 K. The technology offers prospects for superconducting electronics based on nanobridge Josephson junctions operating within the framework of the Ginzburg–Landau theory at 4.2 K.

ACS Style

Michael Faley; Yuchen Liu; Rafal Dunin-Borkowski. Titanium Nitride as a New Prospective Material for NanoSQUIDs and Superconducting Nanobridge Electronics. Nanomaterials 2021, 11, 466 .

AMA Style

Michael Faley, Yuchen Liu, Rafal Dunin-Borkowski. Titanium Nitride as a New Prospective Material for NanoSQUIDs and Superconducting Nanobridge Electronics. Nanomaterials. 2021; 11 (2):466.

Chicago/Turabian Style

Michael Faley; Yuchen Liu; Rafal Dunin-Borkowski. 2021. "Titanium Nitride as a New Prospective Material for NanoSQUIDs and Superconducting Nanobridge Electronics." Nanomaterials 11, no. 2: 466.

Accepted manuscript
Published: 11 January 2021 in Superconductor Science and Technology
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Nanometer-scale superconducting quantum interference devices (nanoSQUIDs) were fabricated within a distance of 1 µm from the corners of 2 mm × 2 mm × 0.05 mm Si cantilevers that are intended for use in a scanning nanoSQUID microscope. The nanoSQUIDs contained Josephson junctions (JJs) in the form of Nb-based nanobridges, which had widths down to 10 nm and were patterned using HSQ negative resist. Numerical simulations of the superconducting current and the spatial distribution of the order parameter in the nanobridge JJs and the nanoSQUID, as well as the current-phase relationship in the nanobridge JJs, were performed according to Ginzburg-Landau equations on one-dimensional and two-dimensional grids. Bulk micromachining of the Si cantilever was performed using reactive ion etching with SF6 gas through masks of nLOF 2020 photoresist from the front side and a quartz shadow mask from the back side of the substrate. An etch rate of 6 µm/min for Si was achieved for a power of 300 W of the inductively coupled SF6 plasma. The nanoSQUIDs exhibited non-hysteretic current-voltage characteristics on the cantilever. The estimated spin sensitivity of 48 µB/√Hz is sufficient for use of such a nanoSQUID as a magnetic field sensor for studying nanoscale objects, with a projected total distance to the object of below 100 nm.

ACS Style

Michael Faley; Timur Bikulov; Vincent Bosboom; Alexander A Golubov; Rafal E Dunin-Borkowski. Bulk nanomachining of cantilevers with Nb nanoSQUIDs based on nanobridge Josephson junctions. Superconductor Science and Technology 2021, 34, 035014 .

AMA Style

Michael Faley, Timur Bikulov, Vincent Bosboom, Alexander A Golubov, Rafal E Dunin-Borkowski. Bulk nanomachining of cantilevers with Nb nanoSQUIDs based on nanobridge Josephson junctions. Superconductor Science and Technology. 2021; 34 (3):035014.

Chicago/Turabian Style

Michael Faley; Timur Bikulov; Vincent Bosboom; Alexander A Golubov; Rafal E Dunin-Borkowski. 2021. "Bulk nanomachining of cantilevers with Nb nanoSQUIDs based on nanobridge Josephson junctions." Superconductor Science and Technology 34, no. 3: 035014.

Journal article
Published: 22 June 2020 in Applied Physics Letters
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The interfaces in oxide heterostructures that bring novel physical phenomena and functionalities have attracted great attention in fundamental research and device applications. For uncovering structure–property relationships of oxide heterostructures, direct evidence of the atomic-scale structure of heterointerfaces is highly desired. Here, we report on studying the structure of interfaces between YBa2Cu3O7-δ thin films and SrTiO3 substrates by means of aberration-corrected ultrahigh-resolution electron microscopy. Employing advanced imaging and spectroscopic techniques, shifts of atoms at the interface away from the regular lattice sites are measured, leading to the interfacial polarity. The local polarization induced by the atomic shifts directs toward the cuprate films and is estimated to be about 36.1 μC/cm2. The observed interfacial polar layer is understood by the special atomic configuration across the interface, which could modulate the electrical properties in superconducting devices that are based on the ferroelectric/superconductor heterosystems.

ACS Style

Shao-Bo Mi; Tian Yao; Shao-Dong Cheng; Michael Faley; Ulrich Poppe; Lu Lu; Dawei Wang; Chun-Lin Jia. Atomic-scale imaging of interfacial polarization in cuprate-titanate heterostructures. Applied Physics Letters 2020, 116, 251603 .

AMA Style

Shao-Bo Mi, Tian Yao, Shao-Dong Cheng, Michael Faley, Ulrich Poppe, Lu Lu, Dawei Wang, Chun-Lin Jia. Atomic-scale imaging of interfacial polarization in cuprate-titanate heterostructures. Applied Physics Letters. 2020; 116 (25):251603.

Chicago/Turabian Style

Shao-Bo Mi; Tian Yao; Shao-Dong Cheng; Michael Faley; Ulrich Poppe; Lu Lu; Dawei Wang; Chun-Lin Jia. 2020. "Atomic-scale imaging of interfacial polarization in cuprate-titanate heterostructures." Applied Physics Letters 116, no. 25: 251603.

Conference paper
Published: 20 June 2020 in Journal of Physics: Conference Series
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We have developed nanoSQUIDs with Josephson junctions in the form of Nb nanobridges, whose thickness, width and length are in the order of the superconducting coherence length in Nb thin films, which is 15 nm at 4.2 K in 20-nm-thick films. The thin Nb films were deposited using pulsed DC magnetron sputtering. A 30-nm-thick mask of PMMA resist was formed by electron beam exposure using a dose of 50 mC/cm2 at 100 kV, at which PMMA operates as a high-resolution negative resist. Compared to the previously used HSQ resist, PMMA has a much better availability, lower health risk, a longer shelf life and a simpler development procedure, while maintaining sufficient resolution. Both Nb nanobridges with widths down to 10 nm and nanoSQUIDs with the incorporated nanobridges were fabricated using reactive ion etching with pure SF6 gas. They show non-hysteretic I(V)-characteristics and a modulation of the critical current at both directly injected or externally applied magnetic field fluxes. The obtained spin sensitivity of is very promising for the use of the nanoSQUIDs as magnetic field sensors for the investigation of nanoscale objects.

ACS Style

R. Rodrigo; Michael Faley; R.E. Dunin-Borkowski. NanoSQUIDs based on Nb nanobridges. Journal of Physics: Conference Series 2020, 1559, 012011 .

AMA Style

R. Rodrigo, Michael Faley, R.E. Dunin-Borkowski. NanoSQUIDs based on Nb nanobridges. Journal of Physics: Conference Series. 2020; 1559 (1):012011.

Chicago/Turabian Style

R. Rodrigo; Michael Faley; R.E. Dunin-Borkowski. 2020. "NanoSQUIDs based on Nb nanobridges." Journal of Physics: Conference Series 1559, no. 1: 012011.

Journal article
Published: 07 May 2020 in Superconductor Science and Technology
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ACS Style

Andrey Shishkin; Olga Victorovna Skryabina; Vladimir Gurtovoi; Sergey Dizhur; Michael Faley; Alexander A Golubov; V S Stolyarov. Planar MoRe-based direct current nanoSQUID. Superconductor Science and Technology 2020, 33, 065005 .

AMA Style

Andrey Shishkin, Olga Victorovna Skryabina, Vladimir Gurtovoi, Sergey Dizhur, Michael Faley, Alexander A Golubov, V S Stolyarov. Planar MoRe-based direct current nanoSQUID. Superconductor Science and Technology. 2020; 33 (6):065005.

Chicago/Turabian Style

Andrey Shishkin; Olga Victorovna Skryabina; Vladimir Gurtovoi; Sergey Dizhur; Michael Faley; Alexander A Golubov; V S Stolyarov. 2020. "Planar MoRe-based direct current nanoSQUID." Superconductor Science and Technology 33, no. 6: 065005.

Accepted manuscript
Published: 27 January 2020 in Superconductor Science and Technology
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We have developed Josephson junctions between the d-wave superconductor YBa2Cu3O7-x (YBCO) and the s-wave Mo0.6Re0.4 (MoRe) alloy superconductor. Such ds Josephson junctions (ds-JJs) are of interest for superconducting electronics making use of incorporated π-phase shifts. The I(V)-characteristics of the ds-JJs demonstrate a twice larger critical current along the [100] axis of the YBCO film compared to similarly-oriented ds-JJs made with a Nb top electrode. The characteristic voltage IcRn of the YBCO-Au-MoRe (YBCO-MoRe) ds-JJs is 750 µV at 4.2 K. The ds-JJs that are oriented along the [100] or [010] axes of the YBCO film exhibit a 200-times higher critical current than similar ds-JJs oriented along the [110] axis of the same YBCO film. A critical current density Jc = 20 kA/cm2 at 4.2 K was achieved. Different layouts of π-loops based on the novel ds-JJs were arranged in various mutual coupling configurations. Spontaneous persistent currents in the π-loops were investigated using scanning SQUID microscopy. Magnetic states of the π-loops were manipulated by currents in integrated bias lines. Higher flux states up to ±2.5Φ0 were induced and stabilized in the π-loops. Crossover temperatures between thermally activated and quantum tunneling switching processes in the ds-JJs were estimated. The demonstrated ability to stabilize and manipulate states of π-loops paves the way towards new computing concepts such as quantum annealing computing.

ACS Style

Michael Faley; P. Reith; C D Satrya; V S Stolyarov; B. Folkers; Alexander A Golubov; H. Hilgenkamp; Rafal E Dunin-Borkowski. MoRe/YBCO Josephson junctions and π-loops. Superconductor Science and Technology 2020, 33, 044005 .

AMA Style

Michael Faley, P. Reith, C D Satrya, V S Stolyarov, B. Folkers, Alexander A Golubov, H. Hilgenkamp, Rafal E Dunin-Borkowski. MoRe/YBCO Josephson junctions and π-loops. Superconductor Science and Technology. 2020; 33 (4):044005.

Chicago/Turabian Style

Michael Faley; P. Reith; C D Satrya; V S Stolyarov; B. Folkers; Alexander A Golubov; H. Hilgenkamp; Rafal E Dunin-Borkowski. 2020. "MoRe/YBCO Josephson junctions and π-loops." Superconductor Science and Technology 33, no. 4: 044005.

Journal article
Published: 10 January 2019 in IEEE Transactions on Applied Superconductivity
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We fabricated Josephson junctions (JJs) between the d-wave superconductor (SC) YBa $_2$ Cu $_3$ O $_27 -x (YBCO) and the s-wave SC Nb (ds-JJs) on graphoepitaxially buffered MgO sub-strates, studied ds-JJs at temperatures down to 30 mK and em-ployed these JJs in π-loops. Current-voltage characteristics of ds-JJs oriented along the [100] axis of YBCO exhibited up to a fac-tor of 200 higher critical current densities than ds-JJs oriented along the [110] axis of YBCO. The critical current Ic and the IcRn product of [100]-oriented 3 μm wide ds-JJs are ∼70 μA and ∼200 μV, respectively, at 4.2 K. Rectangular arrays of up to 40000 π-loops based on such ds-JJs were investigated using a low temperature scanning SQUID microscope. We observed ordering of spontaneously generated half integer magnetic flux quanta in the π-loops correlated with minute spurious background magnet-ic fields, as well as with configurations and mutual coupling of the π-loops. We manipulated the magnetic states of the π-loops by the local application of magnetic fields using nearby planar coils. Our work paves the way for the use of π-loops in computations that are based on annealing processes.

ACS Style

Michael I. Faley; P. Reith; V. S. Stolyarov; I. A. Golovchanskiy; A. A. Golubov; Hans Hilgenkamp; R. E. Dunin-Borkowski; Rafal Dunin-Borkowski. π-Loops With ds Josephson Junctions. IEEE Transactions on Applied Superconductivity 2019, 29, 1 -5.

AMA Style

Michael I. Faley, P. Reith, V. S. Stolyarov, I. A. Golovchanskiy, A. A. Golubov, Hans Hilgenkamp, R. E. Dunin-Borkowski, Rafal Dunin-Borkowski. π-Loops With ds Josephson Junctions. IEEE Transactions on Applied Superconductivity. 2019; 29 (5):1-5.

Chicago/Turabian Style

Michael I. Faley; P. Reith; V. S. Stolyarov; I. A. Golovchanskiy; A. A. Golubov; Hans Hilgenkamp; R. E. Dunin-Borkowski; Rafal Dunin-Borkowski. 2019. "π-Loops With ds Josephson Junctions." IEEE Transactions on Applied Superconductivity 29, no. 5: 1-5.

Journal article
Published: 09 January 2018 in IEEE Transactions on Applied Superconductivity
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We have combined a flip-chip high-T$c$ DC SQUID magnetometer with a ferromagnetic flux antenna made from 250 insulated 25-μ-thick stripes of amorphous soft magnetic Vitrovac 6025 foil inserted through the pick-up loop of the superconducting flux transformer. The ferromagnetic flux antenna provides improved magnetic coupling of the high-T$c$ SQUID to magnetic fields of ~0.4 nT/Φ$_0$ to ~0.18 nT/Φ$_0$. The orientation of the stripes was chosen to be normal to the foil tape rolling direction, in order to minimize contributions from Barkhausen noise. A magnetic field resolution of ~2 fT/$\surd$Hz at 1 kHz and 77 K was achieved. Details of the technology and noise spectra of the novel composite high-T$c$ SQUID sensor are presented and their prospective applications for biomagnetic research and non-destructive evaluation are discussed.

ACS Style

Michael I. Faley; Yuri V. Maslennikov; Valery P. Koshelets; Rafal E. Dunin-Borkowski. Flip-Chip High-Tc DC SQUID Magnetometer With a Ferromagnetic Flux Antenna. IEEE Transactions on Applied Superconductivity 2018, 28, 1 -5.

AMA Style

Michael I. Faley, Yuri V. Maslennikov, Valery P. Koshelets, Rafal E. Dunin-Borkowski. Flip-Chip High-Tc DC SQUID Magnetometer With a Ferromagnetic Flux Antenna. IEEE Transactions on Applied Superconductivity. 2018; 28 (4):1-5.

Chicago/Turabian Style

Michael I. Faley; Yuri V. Maslennikov; Valery P. Koshelets; Rafal E. Dunin-Borkowski. 2018. "Flip-Chip High-Tc DC SQUID Magnetometer With a Ferromagnetic Flux Antenna." IEEE Transactions on Applied Superconductivity 28, no. 4: 1-5.

Review
Published: 06 December 2017 in Sensors
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We review stationary and mobile systems that are used for the nondestructive evaluation of room temperature objects and are based on superconducting quantum interference devices (SQUIDs). The systems are optimized for samples whose dimensions are between 10 micrometers and several meters. Stray magnetic fields from small samples (10 µm–10 cm) are studied using a SQUID microscope equipped with a magnetic flux antenna, which is fed through the walls of liquid nitrogen cryostat and a hole in the SQUID’s pick-up loop and returned sidewards from the SQUID back to the sample. The SQUID microscope does not disturb the magnetization of the sample during image recording due to the decoupling of the magnetic flux antenna from the modulation and feedback coil. For larger samples, we use a hand-held mobile liquid nitrogen minicryostat with a first order planar gradiometric SQUID sensor. Low-Tc DC SQUID systems that are designed for NDE measurements of bio-objects are able to operate with sufficient resolution in a magnetically unshielded environment. High-Tc DC SQUID magnetometers that are operated in a magnetic shield demonstrate a magnetic field resolution of ~4 fT/√Hz at 77 K. This sensitivity is improved to ~2 fT/√Hz at 77 K by using a soft magnetic flux antenna.

ACS Style

M. I. Faley; E. A. Kostyurina; K. V. Kalashnikov; Yu. V. Maslennikov; V. P. Koshelets; R. E. Dunin-Borkowski. Superconducting Quantum Interferometers for Nondestructive Evaluation. Sensors 2017, 17, 2798 .

AMA Style

M. I. Faley, E. A. Kostyurina, K. V. Kalashnikov, Yu. V. Maslennikov, V. P. Koshelets, R. E. Dunin-Borkowski. Superconducting Quantum Interferometers for Nondestructive Evaluation. Sensors. 2017; 17 (12):2798.

Chicago/Turabian Style

M. I. Faley; E. A. Kostyurina; K. V. Kalashnikov; Yu. V. Maslennikov; V. P. Koshelets; R. E. Dunin-Borkowski. 2017. "Superconducting Quantum Interferometers for Nondestructive Evaluation." Sensors 17, no. 12: 2798.

Topical review
Published: 04 July 2017 in Superconductor Science and Technology
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In this paper, we review the preparation technology, integration in measurement systems and tests of high-Tc superconducting quantum interference devices (SQUIDs) intended for biomagnetic applications. A focus is on developments specific to Forschungszentrum Jülich GmbH, Chalmers University of Technology, MedTech West, and the University of Gothenburg, while placing these results in the perspective of those achieved elsewhere. Sensor fabrication, including the deposition and structuring of epitaxial oxide heterostructures, materials for substrates, epitaxial bilayer buffers, bicrystal and step-edge Josephson junctions, and multilayer flux transformers are detailed. The properties of the epitaxial multilayer high-Tc direct current SQUID sensors, including their integration in measurement systems with special electronics and liquid nitrogen cryostats, are presented in the context of biomagnetic recording. Applications that include magnetic nanoparticle based molecular diagnostics, magnetocardiography, and magnetoencephalography are presented as showcases of high-Tc biomagnetic systems. We conclude by outlining future challenges.

ACS Style

M I Faley; Jürgen Dammers; Y V Maslennikov; J F Schneiderman; Dag Winkler; V P Koshelets; N J Shah; R E Dunin-Borkowski. High-TcSQUID biomagnetometers. Superconductor Science and Technology 2017, 30, 083001 .

AMA Style

M I Faley, Jürgen Dammers, Y V Maslennikov, J F Schneiderman, Dag Winkler, V P Koshelets, N J Shah, R E Dunin-Borkowski. High-TcSQUID biomagnetometers. Superconductor Science and Technology. 2017; 30 (8):083001.

Chicago/Turabian Style

M I Faley; Jürgen Dammers; Y V Maslennikov; J F Schneiderman; Dag Winkler; V P Koshelets; N J Shah; R E Dunin-Borkowski. 2017. "High-TcSQUID biomagnetometers." Superconductor Science and Technology 30, no. 8: 083001.

Journal article
Published: 21 November 2016 in IEEE Transactions on Applied Superconductivity
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We report the application of a scanning high-Tc SQUID microscope with a ferromagnetic flux guide for the non-destructive evaluation of weld seams and wear tracks and scars on austenitic stainless steel plates as well as measurement of magnetic stray fields distribution above patterned by electron lithography 30nm thick cobalt films. A soft magnetic amorphous Vitrovac foil was used to guide the flux from the samples, which were held at room temperature, to the liquid-nitrogen-cooled SQUID-sensor and back. The flux guide passes through a hole in the 1mm x 2.5mm pick-up loop of the high-T $c$ SQUID sensor, thereby providing improved coupling of the magnetic flux from the object to the SQUID. In order to avoid the influence of the SQUID biasing magnetic field on the object under investigation, a modulation and feedback coil was coupled to the pick-up loop of the SQUID directly and beyond the ferromagnetic flux guide. Such decoupling of feedback coil from soft magnetic flux antenna ensures that the high-T $c$ SQUID microscope does not disturb the sample magnetization during image recording. The SQUID microscope can be used to measure the spatial distribution of the z-component of the stray field above a specimen without mechanical contact to it.

ACS Style

Michael Faley; E. A. Kostyurina; Patrick Diehle; U. Poppe; Y. V. Maslennikov; Valery Koshelets; R. E. Dunin-Borkowski; Andras Kovacs. Nondestructive Evaluation Using a High-Tc SQUID Microscope. IEEE Transactions on Applied Superconductivity 2016, 27, 1 -1.

AMA Style

Michael Faley, E. A. Kostyurina, Patrick Diehle, U. Poppe, Y. V. Maslennikov, Valery Koshelets, R. E. Dunin-Borkowski, Andras Kovacs. Nondestructive Evaluation Using a High-Tc SQUID Microscope. IEEE Transactions on Applied Superconductivity. 2016; 27 (4):1-1.

Chicago/Turabian Style

Michael Faley; E. A. Kostyurina; Patrick Diehle; U. Poppe; Y. V. Maslennikov; Valery Koshelets; R. E. Dunin-Borkowski; Andras Kovacs. 2016. "Nondestructive Evaluation Using a High-Tc SQUID Microscope." IEEE Transactions on Applied Superconductivity 27, no. 4: 1-1.

Journal article
Published: 26 January 2016 in Journal of Communications Technology and Electronics
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Original superconducting quantum interference devices (SQUIDs) with a working temperature of 77 K based on high-temperature superconducting (HTSC) YBa2Cu3O7–x films can be used for the measurement systems of nondestructive testing using magnetic and eddy-current methods. A dynamic range of 120 dB with respect to the amplitude of the measured signal and a spatial resolution of about 10 µm are reached for the measurement system with the HTSC SQUID in which a receiving loop with a size of 50 µm is placed at a distance of about 0.3 mm from the room-temperature object under study. The sensitivity with respect to magnetic field (4 fT/ \(\sqrt {Hz} \) at a temperature of 77 K) of the HTSC SQUID magnetometer with multilayer superconducting flux transformer is sufficient for applications in biomagnetic measurements in magnetocardiography and magnetoencephalography. HTSC SQUID gradiometers with multilayer superconducting flux transformers exhibit stable operation in magnetically unshielded space at a sensitivity of 15 fT/cm \(\sqrt {Hz} \) with respect to the gradient of magnetic field at 77 K. Such a sensitivity is sufficient for the detection of single magnetic particles with a size of about 10 µm at a distance of about 15 mm.

ACS Style

Michael Faley; Yu. V. Maslennikov; Valery Koshelets. Superconducting quantum interference devices based on YBa2Cu3O7–x films for nondestructive testing. Journal of Communications Technology and Electronics 2016, 61, 86 -92.

AMA Style

Michael Faley, Yu. V. Maslennikov, Valery Koshelets. Superconducting quantum interference devices based on YBa2Cu3O7–x films for nondestructive testing. Journal of Communications Technology and Electronics. 2016; 61 (1):86-92.

Chicago/Turabian Style

Michael Faley; Yu. V. Maslennikov; Valery Koshelets. 2016. "Superconducting quantum interference devices based on YBa2Cu3O7–x films for nondestructive testing." Journal of Communications Technology and Electronics 61, no. 1: 86-92.

Journal article
Published: 30 June 2015 in IEEE Transactions on Terahertz Science and Technology
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A superconducting integrated receiver (SIR) comprises all of the elements needed for heterodyne detection on a single chip. Light weight and low power consumption combined with nearly quantum-limited sensitivity and a wide tuning range of the superconducting local oscillator make the SIR a perfect candidate for many practical applications. For the first time, we demonstrated the capabilities of the SIR technology for remote operation under harsh environmental conditions and for heterodyne spectroscopy at atmospheric limb sounding on board a high-altitude balloon. Recently, the SIR was successfully implemented for the first spectral measurements of THz radiation emitted from intrinsic Josephson junction stacks (BSCCO mesa) at frequencies up to 750 GHz; linewidth below 10 MHz has been recorded in the high bias regime. The phase-locked SIR has been used for the locking of the BSCCO oscillator under the test. To extend the operation range of the SIR well above 1 THz, a new technique for fabrication of high-quality SIS tunnel junctions with gap voltage Vg up to 5.3 mV has been developed. Integration of a superconducting high-harmonic phase detector with a cryogenic oscillator opens a possibility for efficient phase locking of the sources with free-running linewidth up to 30 MHz that is important both for BSCCO mesa and NbN/MgO/NbN oscillators.

ACS Style

Valery P. Koshelets; Arno De Lange; G. De Lange; Vladimir L. Vaks; M. Y. Li; Huabing Wang; Pavel N. Dmitriev; Michael I. Faley; Lyudmila V. Filippenko; Konstantin V. Kalashnikov; Nickolay Kinev; Oleg S. Kiselev; Anton A. Artanov; Kirill I. Rudakov. Superconducting Integrated Terahertz Spectrometers. IEEE Transactions on Terahertz Science and Technology 2015, 5, 687 -694.

AMA Style

Valery P. Koshelets, Arno De Lange, G. De Lange, Vladimir L. Vaks, M. Y. Li, Huabing Wang, Pavel N. Dmitriev, Michael I. Faley, Lyudmila V. Filippenko, Konstantin V. Kalashnikov, Nickolay Kinev, Oleg S. Kiselev, Anton A. Artanov, Kirill I. Rudakov. Superconducting Integrated Terahertz Spectrometers. IEEE Transactions on Terahertz Science and Technology. 2015; 5 (4):687-694.

Chicago/Turabian Style

Valery P. Koshelets; Arno De Lange; G. De Lange; Vladimir L. Vaks; M. Y. Li; Huabing Wang; Pavel N. Dmitriev; Michael I. Faley; Lyudmila V. Filippenko; Konstantin V. Kalashnikov; Nickolay Kinev; Oleg S. Kiselev; Anton A. Artanov; Kirill I. Rudakov. 2015. "Superconducting Integrated Terahertz Spectrometers." IEEE Transactions on Terahertz Science and Technology 5, no. 4: 687-694.

Journal article
Published: 27 October 2014 in IEEE Transactions on Applied Superconductivity
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We have analyzed the possibility to construct multichannel magnetoencephalography (MEG) systems based on high-Tc direct current superconducting quantum interference devices (DC SQUIDs) with graphoepitaxial step edge Josephson junctions. A new layout of multilayer high-Tc superconducting flux transformers was tested and a new type of high-Tc DC SQUID magnetometer intended for MEG systems was realized. ameter 24 mm and a magnetic field resolution of ~4 fT/√Hz These magnetometers have a vacuum-tight capsule of outer diat 77 K. Crosstalk between adjacent sensors was estimated and measured for in-plane and axial configurations. The vibration-free cooling of sensors, minimization of the sensor-to-object distance and optimization of the sensor positions as well as the gantry design are discussed. Our findings may have implications for the next generation of noninvasive imaging techniques that will be used to understand human brain function.

ACS Style

M. I. Faley; I. A. Gerasimov; O. M. Faley; Harald Chocholacs; Jürgen Dammers; Eberhard Eich; F. Boers; N. J. Shah; A. S. Sobolev; V. Yu. Slobodchikov; Yu. V. Maslennikov; V. P. Koshelets; R. E. Dunin-Borkowski. Integration Issues of Graphoepitaxial High- ${\rm T}_{\rm c}$ SQUIDs Into Multichannel MEG Systems. IEEE Transactions on Applied Superconductivity 2014, 25, 1 -5.

AMA Style

M. I. Faley, I. A. Gerasimov, O. M. Faley, Harald Chocholacs, Jürgen Dammers, Eberhard Eich, F. Boers, N. J. Shah, A. S. Sobolev, V. Yu. Slobodchikov, Yu. V. Maslennikov, V. P. Koshelets, R. E. Dunin-Borkowski. Integration Issues of Graphoepitaxial High- ${\rm T}_{\rm c}$ SQUIDs Into Multichannel MEG Systems. IEEE Transactions on Applied Superconductivity. 2014; 25 (3):1-5.

Chicago/Turabian Style

M. I. Faley; I. A. Gerasimov; O. M. Faley; Harald Chocholacs; Jürgen Dammers; Eberhard Eich; F. Boers; N. J. Shah; A. S. Sobolev; V. Yu. Slobodchikov; Yu. V. Maslennikov; V. P. Koshelets; R. E. Dunin-Borkowski. 2014. "Integration Issues of Graphoepitaxial High- ${\rm T}_{\rm c}$ SQUIDs Into Multichannel MEG Systems." IEEE Transactions on Applied Superconductivity 25, no. 3: 1-5.

Journal article
Published: 26 May 2014 in Applied Physics Letters
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To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography(MEG)systems are equipped with low-temperature (low-Tc) superconducting quantum interference device(SQUID)sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-TcSQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-Tc SQUID-based MEGsystems.

ACS Style

Jürgen Dammers; Harald Chocholacs; Eberhard Eich; Frank Boers; Michael Faley; Rafal E. Dunin-Borkowski; N. Jon Shah. Source localization of brain activity using helium-free interferometer. Applied Physics Letters 2014, 104, 213705 .

AMA Style

Jürgen Dammers, Harald Chocholacs, Eberhard Eich, Frank Boers, Michael Faley, Rafal E. Dunin-Borkowski, N. Jon Shah. Source localization of brain activity using helium-free interferometer. Applied Physics Letters. 2014; 104 (21):213705.

Chicago/Turabian Style

Jürgen Dammers; Harald Chocholacs; Eberhard Eich; Frank Boers; Michael Faley; Rafal E. Dunin-Borkowski; N. Jon Shah. 2014. "Source localization of brain activity using helium-free interferometer." Applied Physics Letters 104, no. 21: 213705.

Conference paper
Published: 12 May 2014 in Journal of Physics: Conference Series
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M I Faley; D Meertens; U Poppe; Rafal Dunin-Borkowski. Graphoepitaxial high-TcSQUIDs. Journal of Physics: Conference Series 2014, 507, 1 .

AMA Style

M I Faley, D Meertens, U Poppe, Rafal Dunin-Borkowski. Graphoepitaxial high-TcSQUIDs. Journal of Physics: Conference Series. 2014; 507 (4):1.

Chicago/Turabian Style

M I Faley; D Meertens; U Poppe; Rafal Dunin-Borkowski. 2014. "Graphoepitaxial high-TcSQUIDs." Journal of Physics: Conference Series 507, no. 4: 1.

Conference paper
Published: 01 July 2013 in 2013 IEEE 14th International Superconductive Electronics Conference (ISEC)
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We have prepared high-T c superconducting heterostructures for DC SQUIDs with graphoepitaxial step edge Josephson junctions on single crystal MgO substrates and investigated them using complementary characterization techniques, including atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy. Combined epitaxial (out-of-plane) and graphoepitaxial (in-plane) growth of YBa 2 Cu 3 O 7-x (YBCO) films on the tilted surfaces of step edges on MgO substrates was observed. The high-T c step-edge Josephson junctions demonstrated a good reproducibility and an I c R n product of about 600 μV at 77 K. The DC SQUIDs with step edge junctions showed voltage swings δVpp of up to about 60 μV at 77 K. High values of R n of the graphoepitaxial step edge Josephson junctions can be advantageous for their applications as qubits.

ACS Style

M. I. Faley; D. Meertens; Ulrich Poppe; R. E. Dunin-Borkowski. Graphoepitaxial Josephson junctions and DC SQUIDs. 2013 IEEE 14th International Superconductive Electronics Conference (ISEC) 2013, 1 -3.

AMA Style

M. I. Faley, D. Meertens, Ulrich Poppe, R. E. Dunin-Borkowski. Graphoepitaxial Josephson junctions and DC SQUIDs. 2013 IEEE 14th International Superconductive Electronics Conference (ISEC). 2013; ():1-3.

Chicago/Turabian Style

M. I. Faley; D. Meertens; Ulrich Poppe; R. E. Dunin-Borkowski. 2013. "Graphoepitaxial Josephson junctions and DC SQUIDs." 2013 IEEE 14th International Superconductive Electronics Conference (ISEC) , no. : 1-3.

Journal article
Published: 20 November 2012 in IEEE Transactions on Applied Superconductivity
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We have investigated the microstructural and electron transport properties of 45° step-edge Josephson junctions grown on MgO substrates and used them for the preparation of superconducting quantum interference device (SQUID) magnetometers intended for magnetoencephalography (MEG) measurement systems. The high-Tc SQUID magnetometers also incorporate 16 mm multilayer superconducting flux transformers on the MgO substrates and demonstrate a magnetic field resolution of ~ 4 fT/√Hz at 77 K. Results are illustrated for the detection of auditory evoked magnetic responses of the human cortex and compared between high-Tc SQUIDs and a commercial low-Tc MEG system. Our results demonstrate that MEG systems can be upgraded using high-Tc SQUIDs to make them independent of helium and more user-friendly, saving operating costs and leading to the widespread utilization of MEG systems in clinical practice and at universities.

ACS Style

M. I. Faley; U. Poppe; R. E. Dunin-Borkowski; M. Schiek; F. Boers; H. Chocholacs; J. Dammers; E. Eich; N. J. Shah; A. B. Ermakov; V. Y. Slobodchikov; Y. V. Maslennikov; V. P. Koshelets. High-$T_{\rm c}$ DC SQUIDs for Magnetoencephalography. IEEE Transactions on Applied Superconductivity 2012, 23, 1600705 -1600705.

AMA Style

M. I. Faley, U. Poppe, R. E. Dunin-Borkowski, M. Schiek, F. Boers, H. Chocholacs, J. Dammers, E. Eich, N. J. Shah, A. B. Ermakov, V. Y. Slobodchikov, Y. V. Maslennikov, V. P. Koshelets. High-$T_{\rm c}$ DC SQUIDs for Magnetoencephalography. IEEE Transactions on Applied Superconductivity. 2012; 23 (3):1600705-1600705.

Chicago/Turabian Style

M. I. Faley; U. Poppe; R. E. Dunin-Borkowski; M. Schiek; F. Boers; H. Chocholacs; J. Dammers; E. Eich; N. J. Shah; A. B. Ermakov; V. Y. Slobodchikov; Y. V. Maslennikov; V. P. Koshelets. 2012. "High-$T_{\rm c}$ DC SQUIDs for Magnetoencephalography." IEEE Transactions on Applied Superconductivity 23, no. 3: 1600705-1600705.

Journal article
Published: 08 September 2012 in Physics Procedia
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We describe tests of the use of a multilayer highTc DC SQUID magnetometer for magnetoencephalography (MEG) and compare our measurements with results obtained using a lowTc SQUID sensor. The integration of bias reversal readout electronics for highTc DC SQUID magnetometry into a commercial MEG data acquisition system is demonstrated. Results of measurements performed on a salinefilled head phantom are shown and the detection of an auditory evoked magnetic response of the human cortex elicited by a stimulus is illustrated. Future modifications of highTc DC SQUID sensors for applications in MEG, in order to reach a resolution of 1 fT/√Hz at 77.5 K over a wide frequency band, are outlined.

ACS Style

M.I. Faley; U. Poppe; Rafal Dunin-Borkowski; M. Schiek; F. Boers; H. Chocholacs; J. Dammers; E. Eich; N.J. Shah; A.B. Ermakov; V.Yu. Slobodchikov; Yu.V. Maslennikov; V.P. Koshelets. Magnetoencephalography using a Multilayer hightc DC SQUID Magnetometer. Physics Procedia 2012, 36, 66 -71.

AMA Style

M.I. Faley, U. Poppe, Rafal Dunin-Borkowski, M. Schiek, F. Boers, H. Chocholacs, J. Dammers, E. Eich, N.J. Shah, A.B. Ermakov, V.Yu. Slobodchikov, Yu.V. Maslennikov, V.P. Koshelets. Magnetoencephalography using a Multilayer hightc DC SQUID Magnetometer. Physics Procedia. 2012; 36 ():66-71.

Chicago/Turabian Style

M.I. Faley; U. Poppe; Rafal Dunin-Borkowski; M. Schiek; F. Boers; H. Chocholacs; J. Dammers; E. Eich; N.J. Shah; A.B. Ermakov; V.Yu. Slobodchikov; Yu.V. Maslennikov; V.P. Koshelets. 2012. "Magnetoencephalography using a Multilayer hightc DC SQUID Magnetometer." Physics Procedia 36, no. : 66-71.

Book chapter
Published: 27 June 2011 in Applications of High-Tc Superconductivity
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Michael Faley. Epitaxial Oxide Heterostructures for Ultimate High-Tc Quantum Interferometers. Applications of High-Tc Superconductivity 2011, 1 .

AMA Style

Michael Faley. Epitaxial Oxide Heterostructures for Ultimate High-Tc Quantum Interferometers. Applications of High-Tc Superconductivity. 2011; ():1.

Chicago/Turabian Style

Michael Faley. 2011. "Epitaxial Oxide Heterostructures for Ultimate High-Tc Quantum Interferometers." Applications of High-Tc Superconductivity , no. : 1.