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Full-Text Articles in Physics
Pointer States Via Engineered Dissipation, Kaveh Khodjasteh, Viatcheslav V. V. Dobrovitski, Lorenza Viola
Pointer States Via Engineered Dissipation, Kaveh Khodjasteh, Viatcheslav V. V. Dobrovitski, Lorenza Viola
Dartmouth Scholarship
Pointer states are long-lasting high-fidelity states in open quantum systems. We show how any pure state in a non-Markovian open quantum system can be made to behave as a pointer state by suitably engineering the coupling to the environment via open-loop periodic control. Engineered pointer states are constructed as approximate fixed points of the controlled open-system dynamics, in such a way that they are guaranteed to survive over a long time with a fidelity determined by the relative precision with which the dynamics is engineered. We provide quantitative minimum-fidelity bounds by identifying symmetry and ergodicity conditions that the decoherence-inducing perturbation …
Coherent-State Transfer Via Highly Mixed Quantum Spin Chains, Paola Cappellaro, Lorenza Viola, Chandrasekhar Ramanathan
Coherent-State Transfer Via Highly Mixed Quantum Spin Chains, Paola Cappellaro, Lorenza Viola, Chandrasekhar Ramanathan
Dartmouth Scholarship
Spin chains have been proposed as quantum wires in many quantum-information processing architectures. Coherent transmission of quantum information in spin chains over short distances is enabled by their internal dynamics, which drives the transport of single-spin excitations in perfectly polarized chains. Given the practical challenge of preparing the chain in a pure state, we propose to use a chain that is initially in the maximally mixed state. We compare the transport properties of pure and mixed-state chains and find similarities that enable the experimental study of pure-state transfer via mixed-state chains. We also demonstrate protocols for the perfect transfer of …