Extraction of autonomous quantum coherences

Abstract

Quantum coherence is an essential resource to gain advantage over classical physics and technology. Recently, it has been proposed that a low-temperature environment can induce quantum coherence of a spin without an external coherent pump. We address a critical question if such coherence is extractable by a weak coupling to an output system dynamically affecting back the spin-environment coupling. Describing the entire mechanism, we prove that such extraction is generically possible for output spins (also oscillators or fields) and, as well, in a fermionic analogue of such a process. We compare the internal spin coherence and output coherence over temperature and characteristic frequencies. The proposed optimal coherence extraction opens paths for the upcoming experimental tests with atomic and solid-state systems.

45 pages, 17 figures, Accepted in "Quantum" 2022-03-31

References in corpus (3)

• Sub-millihertz magnetic spectroscopy with a nanoscale quantum sensor
• Observation of a quantum phase transition in the quantum Rabi model with a single trapped ion
• Fundamental limitations in Lindblad descriptions of systems weakly coupled to baths

Cited by in corpus (4)

• Thermally-induced qubit coherence in quantum electromechanics
• Negative Wigner function by decaying interaction from equilibrium
• Nonclassical radiation from a nonlinear oscillator driven solely by classical $1/f$ noise
• Synthesizing and multiplexing autonomous quantum coherences