Directional Quantum State Transfer by Dissipation II – Implementation in Circuit QED

Dissipation is a remarkable resource in quantum information processing that can be used to stabilize and manipulate quantum states or manifolds. Here we utilize dissipation to implement an autonomous technique for quantum state transfer, with built-in directionality, that eliminates the need for time dependent external control. We report experimental progress towards this state transfer in a 3D superconducting circuit QED system between a three-level transmon (Alice) and a coaxial storage cavity (Bob). The quantum state is irreversibly transferred from Alice to Bob via dissipation of a coupled axillary transmon reservoir, activated by two four-wave mixing processes produced by off-resonant drives. Using virtual states of the reservoir to compensate for unwanted dispersive frequency shift, we show that quantum coherence can be maintained throughout the dissipative process, leading to high-fidelity state transfer which is limited by inherent qubit/cavity decoherence.

* Reference: arXiv: 1809.03571 (2018)