Dynamical creation of entanglement by homodyne-mediated feedback (9 pages)

Jin Wang, Howard M. Wiseman, Gerard J Milburn

Jin Wang

Jin Wang, Howard M. Wiseman, Gerard J Milburn +1 more

Jin Wang, Howard M. Wiseman, Gerard J Milburn

For two two-level atoms coupled to a single Bosonic mode that is driven and heavily damped, the steady state can be entangled by resonantly driving the system [S. Schneider and G. J. Milburn, Phys. Rev. A 65, 042107 (2002)]. We present a scheme to significantly increase the steady-state entanglement by using homodyne-mediated feedback, in which the Bosonic mode is that of an electromagnetic cavity, the output of which is measured and the resulting homodyne photocurrent is used to modulate the field driving the qubits. Such feedback can increase the nonlinear response to both the decoherence process of the two-qubit system and the coherent evolution of individual qubits. We present the properties of the entangled states using the SO(3) $Q$ function.

Zhuo Liu, Lülin Kuang, Kai Hu +4 more

In a solid-state circuit QED system, we demonstrate that a homodyne-current-based feedback can create and stabilize highly entangled two-qubit states in the presence of a moderate noisy environment. Particularly, we present an extended analysis for the current-based Markovian feedback, which leads to an improved feedback scheme. We show that this is essential to achieve a desirable control effect by the use of dispersive measurement.

Mohamed Amazioug, Jia‐Xin Peng, Denys Dutykh +1 more