We propose a simple method to simulate and detect topological insulators with cold atoms trapped in a one-dimensional bichromatic optical lattice subjected to a time-periodic modulation. The tight-binding form of this shaken system is equivalent to the periodically driven Aubry-Andre model. We demonstrate that this model can be mapped into a two-dimensional Chern insulator model, whose energy spectrum hosts a topological phase within an experimentally accessible parameter regime. By tuning the laser phase adiabatically, such one-dimensional system constitutes a natural platform to realize topological particle pumping. We show that the Chern number characterizing the topological features of this system can be measured by detecting the density shift after one cycle of pumping.
We extend the recent result of a bipartite Bell singlet [A. W. Carr and M. Saffman, Phys. Rev. Lett. 111, 033607 (2013)] to a stationary three-dimensional entanglement between two-individual neutral Rydberg atoms. This proposal makes full use of the coherent dynamics provided by a Rydberg-mediated interaction and the dissipative factor originating from the spontaneous emission of a Rydberg state. The numerical simulation of the master equation reveals that both the target state negativity and fidelity can exceed 99.90%. Furthermore, a steady three-atom singlet state is also achievable based on the same mechanism.
We introduce a conceptually simple and experimentally feasible method to realize and detect photonic topological Chern insulators with a one-dimensional circuit quantum electrodynamics lattice. By periodically modulating the couplings in this lattice, we show that this one-dimensional model can be mapped into a two-dimensional Chern insulator model. In addition to allowing the study of photonic Chern insulators, this approach also provides a natural platform to realize experimentally Laughlin's pumping argument. Remarkably, based on the scattering theory of topological insulators and input-output formalism, we find that both the photonic edge state and topological invariant can be unambiguously probed with a simple dissipative few-resonator circuit-QED network.
Quantum networks provide a prominent platform for realizing quantum information processing and quantum communication, with entanglement being a key resource in such applications. Here we describe the dissipative transport protocol for entangled states, where entanglement stored in the first node of a quantum network can be transported with high fidelity to the second node via a one-dimensional chiral waveguide. In particular, we exploit the directional asymmetry in chirally coupled single-mode ring resonators to transport entangled states. For the fully chiral waveguide, Bell states, multipartite states, and and Dicke states can be transported with fidelity as high as 0.954, despite the fact that the communication channel is noisy. Our proposal can be utilized for the long-distance distribution of multipartite entangled states between the quantum nodes of an open quantum network.
Chiral quantum networks provide a promising route for realizing quantum information processing and quantum communication. Here we describe how two distant quantum nodes of chiral quantum network become dynamically entangled by a photon transfer through a common one-dimensional chiral waveguide. We harness the directional asymmetry in chirally coupled single-mode ring resonators to generate an entangled state between two atoms. We report a concurrence of up to 0.969, a huge improvement over 0.736, which was suggested and analyzed in great detail in Gonzalez-Ballestero et al. [ Phys. Rev. B 92, 155304 (2015)]. This significant enhancement is achieved by introducing microresonators which serve as an efficient photonic interface between light and matter. The robustness of our protocol to experimental imperfections such as fluctuations in internodal distance, imperfect chirality, various detunings, and atomic spontaneous decay is demonstrated. Our proposal can be utilized for long-distance entanglement generation in quantum networks, which is a key ingredient for many applications in quantum computing and quantum information processing.