Daniel Granados

Prof. Dr. Daniel Granados

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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 January 2007 in Applied Physics Letters
Verified
Journal Article
Closed access
BGB. D. Gerardot
B. D. Gerardot
SSS. Seidl
S. Seidl
PDP. A. Dalgarno
P. A. Dalgarno
RWR. J. Warburton
R. J. Warburton
DGDaniel Granados
Daniel Granados
PPP. M. Petroff
P. M. Petroff
The fine structure of the neutral exciton in a single self-assembled InGaAs quantum dot is investigated under the effect of a lateral electric field. Stark shifts up to 1.5meV, an increase in linewidth, and a decrease in photoluminescence intensity were observed due to the electric field. The authors show that the lateral electric field strongly affects the exciton fine-structure splitting due to active manipulation of the single particle wave functions. Remarkably, the splitting can be tuned over large values and through zero.

5 October 2007 in Physical Review Letters
Verified
Journal Article
Closed access
PDF file
NKN. A. J. M. Kleemans
N. A. J. M. Kleemans
IBI. M. A. Bominaar-Silkens
I. M. A. Bominaar-Silkens
VFV. M. Fomin
V. M. Fomin
VGV. N. Gladilin
V. N. Gladilin
DGDaniel Granados
Daniel Granados
PKP. M. Koenraad
P. M. Koenraad
We report the direct measurement of the persistent current carried by a single electron by means of magnetization experiments on self-assembled InAs/GaAs quantum rings. We measured the first Aharonov-Bohm oscillation at a field of 14 T, in perfect agreement with our model based on the structural properties determined by cross-sectional scanning tunneling microscopy measurements. The observed oscillation magnitude of the magnetic moment per electron is remarkably large for the topology of our nanostructures, which are singly connected and exhibit a pronounced shape asymmetry.

14 April 2003 in Applied Physics Letters
Verified
Journal Article
Closed access
DGDaniel Granados
Daniel Granados
JGJorge M Garcı́a
Jorge M Garcı́a
The effect of growth conditions on the morphological properties of InAs/GaAs(001) quantum dots covered by a thin (<3 nm) GaAs cap has been studied by atomic force microscopy. Each dot turns into an elongated nanostructure at 540 °C upon deposition of the cap in As4 atmosphere, while structures with two humps are obtained when capping at 500 °C. The use of As2 atmosphere instead of As4 at 500 °C leads to the formation of quantum rings. Photoluminescence spectroscopy and polarization photoluminescence (PL) at 15 K show dramatic changes due to the different kinds of confinement. This allows the possibility of tailoring PL emission by controlling the size and shape.

19 September 2005 in Applied Physics Letters
Verified
Journal Article
Closed access
PDF file
POP. Offermans
P. Offermans
PKP. M. Koenraad
P. M. Koenraad
JWJ. H. Wolter
J. H. Wolter
DGDaniel Granados
Daniel Granados
JGJorge M. Garcia
Jorge M. Garcia
JDJ. T. Devreese
J. T. Devreese
We present an atomic-scale analysis of the indium distribution of self-assembled In(Ga)As quantum rings (QRs) which are formed from InAs quantum dots by capping with a thin layer of GaAs and subsequent annealing. We find that the size and shape of QRs as observed by cross-sectional scanning tunneling microscopy (X-STM) deviate substantially from the ring-shaped islands as observed by atomic force microscopy on the surface of uncapped QR structures. We show unambiguously that X-STM images the remaining quantum dot material whereas the AFM images the erupted quantum dot material. The remaining dot material shows an asymmetric indium-rich crater-like shape with a depression rather than an opening at the center and is responsible for the observed electronic properties of QR structures. These quantum craters have an indium concentration of about 55% and a diameter of about 20nm which is consistent with the observed electronic radius of QR structures.

9 November 2005 in Applied Physics Letters
Verified
Journal Article
Closed access
PDF file
JRJ. M. Ripalda
J. M. Ripalda
DGDaniel Granados
Daniel Granados
YGY. González
Y. González
ASA. M. Sánchez
A. M. Sánchez
Sergio I MolinaSergio I Molina
Sergio I Molina
JGJ. M. García
J. M. García
Room temperature photoluminescence at 1.6μm is demonstrated from InGaAs quantum dots capped with an 8nm GaAsSb quantum well. Results obtained from various sample structures are compared, including samples capped with GaAs. The observed redshift in GaAsSb capped samples is attributed to a type II band alignment and to a beneficial modification of growth kinetics during capping due to the presence of Sb. The sample structure is discussed on the basis of transmission electron microscopy results.

29 January 2004 in Nanotechnology
Verified
Journal Article
Closed access
FSFerran Suárez
Ferran Suárez
DGDaniel Granados
Daniel Granados
MDMaría Luisa Dotor
María Luisa Dotor
JGJorge M García
Jorge M García