Quantum phase slips in noncentrosymmetric wires

Develop the theory of quantum phase slips in noncentrosymmetric superconducting wires, including the odd-in-field correction to the instanton action and the resulting quantum diode effect in the phase-slip resistance.

Background

Thermally activated phase slips dominate the regime addressed in the paper, whereas quantum phase slips become important at lower temperatures. The authors argue that the quantum problem should inherit the Lifshitz-invariant structure responsible for the thermally activated barrier asymmetry.

A complete quantum treatment would require calculating the nonreciprocal instanton action and its impact on the resistance, potentially establishing a quantum analogue of the superconducting diode effect.