ABSTRACT
Stationary quantum correlation among two-level systems (TLSs) in steady state is one of unique resources for applications in quantum information processing. Here we propose a scheme to generate such quantum correlation among the TLSs inside a lossy cavity. It is found that, by applying a broadband squeezed laser acting as a squeezed-vacuum reservoir to the cavity, a stable quantum correlation of the TLSs can be generated. By adiabatically eliminating the cavity field, we derive a reduced master equation of the TLSs in the bad-cavity limit. We show that the generated quantum correlation is essentially determined by the squeezing features transferred from the squeezed-vacuum reservoir via the cavity field as a quantum bus. We study the effect of the system parameters, such as the squeezing, the detuning, the coupling strength, and the decay rate of the TLSs, on the performance of the scheme. The feasibility of our proposal is supported by the application of currently available experimental techniques.
ABSTRACT
We propose to simulate and detect quantum anomalous Hall phase with ultracold atoms in a one-dimensional optical lattice, with the other synthetic dimension being realized by modulating spin-orbit coupling. We show that the system manifests a topologically nontrivial phase with two chiral edge states which can be readily detected in this synthetic two-dimensional system. Moreover, it is interesting that at the phase transition point there is a flat energy band and this system can also be in a topologically nontrivial phase with two Fermi zero modes existing at the boundaries by considering the synthetic dimension as a modulated parameter. We also show how to measure these topological phases experimentally in ultracold atoms. Another model with a random Rashba and Dresselhaus spin-orbit coupling strength is also found to exhibit topological nontrivial phase, and the impact of the disorder to the system is revealed.
