Critical behavior in ultra-strong-coupled oscillators

Abstract

We investigate the strong coupling regime of a linear $x$-$x$ coupled harmonic oscillator system, by performing a direct diagonalization of the hamiltonian. It is shown that the $x$-$x$ coupled hamiltonian can be equivalently described by a Mach-Zehnder-type interferometer with a quadratic unitary operation in each of its arms. We show a sharp transition of the unitary operation from an elliptical phase rotator to an elliptical squeezer as the coupling gets stronger, which leads to the continuous generation of entanglement, even for a significantly thermal state, in the ultra-strong coupled regime. It is also shown that this critical regime cannot be achieved by a classical Hookian coupling. Finally, the effect of a finite-temperature environment is analyzed, showing that entanglement can still be generated from a thermal state in the ultra-strong coupled regime, but is destroyed rapidly.

References in corpus (19)

• A computable measure of entanglement
• Circuit Quantum Electrodynamics: Coherent Coupling of a Single Photon to a Cooper Pair Box
• The logarithmic negativity: A full entanglement monotone that is not convex
• Beyond the Jaynes-Cummings model: circuit QED in the ultrastrong coupling regime
• Quantum-coherent coupling of a mechanical oscillator to an optical cavity mode
• Quantum vacuum properties of the intersubband cavity polariton field
• Entanglement by a beam splitter: nonclassicality as a prerequisite for entanglement
• Deep Strong Coupling Regime of the Jaynes-Cummings model
• Entanglement Properties of the Harmonic Chain
• Entanglement induced by a single-mode heat environment
• Symplectic invariants, entropic measures and correlations of Gaussian states
• Pulsed quantum optomechanics
• Subsystem Purity as an Enforcer of Entanglement
• Partial Teleportation of Entanglement in the Noisy Environment
• Towards mechanical entanglement in nano-electromechanical devices
• Bringing entanglement to the high temperature limit
• Single-photon optomechanics in the strong coupling regime
• Dynamical recurrence and the quantum control of coupled oscillators
• Entanglement generation in harmonic chains: tagging by squeezing

Cited by in corpus (15)

• Ultrastrong coupling regimes of light-matter interaction
• Quantum-criticality-induced strong Kerr nonlinearities in optomechanical systems
• Twofold Transition in PT-Symmetric Coupled Oscillators
• Systems of coupled PT-symmetric oscillators
• Strong tunable spin-spin interaction in a weakly coupled nitrogen vacancy spin-cavity electromechanical system
• Dynamics of entanglement between two harmonic modes in stable and unstable regimes
• Local master equations may fail to describe dissipative critical behavior
• Correlations in Quantum Physics
• Linear Ultrastrong Optomechanical Interaction
• Quantum dynamics of two-optical modes and a single mechanical mode optomechanical system: selective energy exchange
• Enhanced Gravitational Entanglement via Modulated Optomechanics
• Parametric Competition in non-autonomous Hamiltonian Systems
• Quantum entanglement and Einstein-Podolsky-Rosen steering in ultrastrongly light-matter coupled system
• Bounding the rotating wave approximation for coupled harmonic oscillators
• Proposal for constraining non-Newtonian gravity at nm range via criticality enhanced measurement of resonance frequency shift