Quantum Reservoir Engineering in Circuit QED

Monday, September 14, 2015
Other Venue
Description: 

Quantum systems are never completely isolated, but instead interact with degrees of freedom in the surrounding environment, eventually leading to decoherence of the system. The conventional route to long-lived quantum coherence involves minimizing coupling to the dissipative bath. Paradoxically, it is possible in principle to instead engineer specific couplings to a quantum environment that allow dissipation to actually create and preserve coherence. I present a simple scheme to engineer the photon shot noise in a microwave cavity so that it relaxes a qubit towards any desired point on the Bloch sphere and which can autonomously stabilize the entanglement of a pair of qubits. More recently we have realized a multi-qubit cooling scheme which preserves the total number of excitation quanta thus paving the way for quantum simulations of the Bose-Hubbard model within the canonical ensemble.