Switching rates in Kerr resonator with two-photon dissipation and driving

TL;DR

This paper analytically studies the switching rates in a Kerr resonator with two-photon dissipation, revealing how detuning and nonlinearity influence quantum bistability and qubit stability, with implications for quantum computing architectures.

Contribution

It provides an analytical expression for the bit-flip error rate in a two-photon driven Kerr oscillator, incorporating effects of detuning and dissipation, validated by numerical simulations.

Findings

Switching rate increases monotonically with detuning in the purely dissipative limit.

Exponential contribution to the bit-flip rate depends nontrivially on system parameters.

Switching rate exhibits a nonmonotonic behavior with detuning under large Kerr nonlinearity.

Abstract

We analytically investigate the switching rate in a two-photon driven Kerr oscillator with finite detuning and two-photon dissipation. This system exhibits quantum bistability and supports a logical manifold for a bosonic qubit. Using Kramer's theory together with the $P$-representation, we derive an analytical expression for the bit-flip error rate within the potential-barrier approximation. The agreement is demonstrated between analytical calculations and numerical simulations obtained by diagonalization of the Liouvillian superoperator. In the purely dissipative limit, the switching rate increases monotonically with detuning, as the two metastable states approach each other in phase space. However, the exponential contribution to the bit-flip rate exhibits a nontrivial dependence on system parameters, extending beyond the naive scaling with the average photon number. In the presence of large Kerr nonlinearity, the switching rate becomes a nonmonotonic function of the detuning and reaches a minimum at a finite detuning. This effect arises because detuning lowers the activation barrier for weak nonlinearity but increases it for large ones, ensuring a minimum of the switching-rate at nonzero detuning. These results establish key conditions for optimizing the performance of critical cat qubits and are directly relevant for the design of scalable superconducting bosonic quantum architectures.