Impact of chaos on the excited-state quantum phase transition of the Kerr parametric oscillator

Abstract

The driven Kerr parametric oscillator, of interest to fundamental physics and quantum technologies, exhibits an excited state quantum phase transition (ESQPT) originating in an unstable classical periodic orbit. The main signature of this type of ESQPT is a singularity in the level density in the vicinity of the energy of the classical separatrix that divides the phase space into two distinct regions. The quantum states with energies below the separatrix are useful for quantum technologies, because they show a cat-like structure that protects them against local decoherence processes. In this work, we show how chaos arising from the interplay between the external drive and the nonlinearities of the system destroys the ESQPT and eventually eliminates the cat states. Our results demonstrate the importance of the analysis of theoretical models for the design of new parametric oscillators with ever larger nonlinearities.

Closest to published version. 4 + pages, 4 figures + Supplemental Material (2 Figs.)

References in corpus (15)

• Switching via quantum activation: A parametrically modulated oscillator
• Excited-state quantum phase transitions
• Kerr-free three-wave mixing in superconducting quantum circuits
• Universal Gate Set for Continuous-Variable Quantum Computation with Microwave Circuits
• On the static effective Hamiltonian of a rapidly driven nonlinear system
• The squeezed Kerr oscillator: spectral kissing and phase-flip robustness
• Observation and manipulation of quantum interference in a superconducting Kerr parametric oscillator
• Spectral kissing and its dynamical consequences in the squeeze-driven Kerr oscillator
• Effective versus Floquet theory for the Kerr parametric oscillator
• Quantum tunneling and level crossings in the squeeze-driven Kerr oscillator
• High-Coherence Kerr-cat qubit in 2D architecture
• Driving superconducting qubits into chaos
• Symmetries of the squeeze-driven Kerr oscillator
• Structurally stable subharmonic regime of a driven quantum Josephson circuit
• Impact of chaos on precursors of quantum criticality

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• Phase transitions, symmetries, and tunneling in Kerr parametric oscillators
• Fundamental Limits to Cat-Code Qubits from Chaos-Assisted Tunneling