Nonlinearity-Induced Entanglement Stability in a Qubit-Oscillator System

Abstract

We propose a system composed of a qubit interacting with a quartic (undriven) nonlinear oscillator (NLO) through a conditional displacement Hamiltonian. We show that even a modest nonlinear perturbation in the NLO potential can enhance and stabilize the quantum entanglement dynamically generated between the qubit and the NLO. In absence of the nonlinearity the entanglement between the qubit and the oscillator is known to periodically oscillate between 0 and 1, whereas the nonlinearity suppresses the dynamical decay of entanglement once it is generated. While the generation of entanglement is due to the superposition principle combined with conditional displacements in the NLO, as noted in several works before, the improvements in this entanglement is because of the squeezing and other complex processes induced by two- and four-phonon interactions. Finally, we have solved the Markovian master equation, and even in this open case the system preserves the previous features and remain robust.

v2: 11 pages, 10 figures (based on the reviewed version)

References in corpus (9)

• Quantum nature of a strongly-coupled single quantum dot-cavity system
• Strong coupling between single-electron tunneling and nano-mechanical motion
• Ultrastrong coupling regime of cavity QED with phase-biased flux qubits
• Large quantum superpositions of a levitated nanodiamond through spin-optomechanical coupling
• Bose-Einstein condensate coupled to a nanomechanical resonator on an atom chip
• Matter Wave Interferometry of a Levitated Thermal Nano-Oscillator Induced and Probed by a Spin
• Quantum Information Processing with Nanomechanical Qubits
• Ion trap transducers for quantum electromechanical oscillators
• Qubit-oscillator system: An analytical treatment of the ultra-strong coupling regime

Cited by in corpus (10)

• Nonlinearity as a resource for nonclassicality in anharmonic systems
• Joint quantum estimation of loss and nonlinearity in driven-dissipative Kerr resonators
• Ground-state cooling of a nanomechanical oscillator with N spins
• Quantum synchronization effects induced by strong nonlinearities
• Macroscopic non-classical state preparation via post-selection
• Arbitrary multimode Gaussian operations on mechanical cluster states
• Generation of entanglement via squeezing on a tripartite-optomechanical system
• Heisenberg-Limited Spin-Mechanical Gravimetry
• Mechanical qubit-light entanglers in hybrid nonlinear qubit-optomechanics
• Anharmonicity can enhance the performance of quantum refrigerators