Two-mode Schrödinger-cat states with nonlinear optomechanics: generation and verification of non-Gaussian mechanical entanglement

Abstract

Cavity quantum optomechanics has emerged as a new platform for quantum science and technology with applications ranging from quantum-information processing to tests of the foundations of physics. Of crucial importance for optomechanics is the generation and verification of non-Gaussian states of motion and a key outstanding challenge is the observation of a canonical two-mode Schrödinger-cat state in the displacement of two mechanical oscillators. In this work, we introduce a pulsed approach that utilizes the nonlinearity of the radiation-pressure interaction combined with photon-counting measurements to generate this entangled non-Gaussian mechanical state, and, importantly, describe a protocol using subsequent pulsed interactions to verify the non-Gaussian entanglement generated. Our pulsed verification protocol allows quadrature moments of the two mechanical oscillators to be measured up to any finite order providing a toolset for experimental characterisation of bipartite mechanical quantum states and allowing a broad range of inseparability criteria to be evaluated. Key experimental factors, such as optical loss and open-system dynamics, are carefully analyzed and we show that the scheme is feasible with only minor improvements to current experiments that operate outside the resolved-sideband regime. Our scheme provides a new avenue for quantum experiments with entangled mechanical oscillators and offers significant potential for further research and development that utilizes such non-Gaussian states for quantum-information and sensing applications, and for studying the quantum-to-classical transition.

36 pages, 6 figures

References in corpus (19)

• Universal Quantum Computation with Continuous-Variable Cluster States
• Entanglement in continuous variable systems: Recent advances and current perspectives
• Two-mode squeezed states in cavity optomechanics via engineering of a single reservoir
• Quantifying the non-Gaussian character of a quantum state by quantum relative entropy
• Quantum-mechanics free subsystem with mechanical oscillators
• Creating and Verifying a Quantum Superposition in a Micro-optomechanical System
• Quantification of Macroscopic Quantum Superpositions within Phase Space
• Optomechanical quantum teleportation
• Quantum State Orthogonalization and a Toolset for Quantum Optomechanical Phonon Control
• Inseparability criteria based on matrices of moments
• Towards Optomechanical Quantum State Reconstruction of Mechanical Motion
• Heralded Preparation and Readout of Entangled Phonons in a Photonic Crystal Cavity
• Non-Gaussian mechanical motion via single and multi-phonon subtraction from a thermal state
• Room-temperature Mechanical Resonator with a Single Added or Subtracted Phonon
• Master-equation treatment of nonlinear optomechanical systems with optical loss
• Storage of polarization-entangled THz-bandwidth photons in a diamond quantum memory
• Hierarchy of Nonlinear Entanglement Dynamics for Continuous Variables
• Preparation and Verification of Two-Mode Mechanical Entanglement Through Pulsed Optomechanical Measurements
• Nanomechanical Design Strategy for Single-Mode Optomechanical Measurement

Cited by in corpus (10)

• Massive quantum systems as interfaces of quantum mechanics and gravity
• Cavity quantum optomechanical nonlinearities and position measurement beyond the breakdown of the linearized approximation
• Optimal quantum parametric feedback cooling
• Dynamical gauge fields with bosonic codes
• Second-Order Coherence Across the Brillouin Lasing Threshold
• Nonlinear optomechanical resonance entering a self-organized energy transfer pattern
• Can the displacemon device test objective collapse models?
• Quantum manipulation of a two-level mechanical system
• Theoretical framework for enhancing or enabling cooling of a mechanical resonator via the anti-Stokes or Stokes interaction and zero-photon detection
• Entanglement dynamics of two modes coupled through a dissipative movable mirror in an optomechanical system