Quantum Kerr parametric oscillators (KPOs) are systems out of equilibrium
with a wide range of applications in quantum computing, quantum sensing, et
fundamental research. They have been realized in superconducting circuits and
photonic platforms. In this work, we explore the onset of ground-state and
excited-state quantum phase transitions in KPOs, focusing on the role of the
phase-space rotational symmetry when the driving frequency is $\mu$ times the
oscillator’s natural frequency, specifically for $\mu=1,2,3,4$. These cases are
experimentally accessible in superconducting circuits, where the Floquet
quasienergy spectrum can also be studied as a function of tunable control
parameters. Using the classical Hamiltonian of the system, we identify the
critical points associated with quantum phase transitions and analyze the
emergence of both real and avoided level crossings, examining their influence
on the energy spectrum and tunneling dynamics. Our findings provide insights
into the engineering of robust quantum states, quantum dynamics control, et
onset of quantum phase transitions with implications for critical quantum
sensing.

Cet article explore les excursions dans le temps et leurs implications.

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