Directional Quantum State Transfer by Dissipation I – Conceptual Overview

Quantum state transfer from an information-carrying qubit to a receiving qubit is ubiquitous for quantum information technology. In a closed quantum system, this task requires precisely-timed control of coherent qubit-qubit interactions that are intrinsically reciprocal. Here, breaking reciprocity by dissipation in an open system, we propose a type of cascaded quantum systems where a quantum state can be spontaneously transferred between stationary qubits without time-dependent control. We show that the minimum system dimension for transferring one qubit of information in this way is 3x2 (between one physical qutrit and one physical qubit), plus one auxiliary reservoir. We discuss general requirements and strategies for such autonomous quantum state transfer as well as its connection with autonomous quantum error correction. We further discuss physical implementation schemes, with our experimental progress in a superconducting circuit QED platform to be described in a following presentation.
* Reference: arXiv: 1809.03571 (2018).