We theoretically consider light storage in a single nanoparticle levitated in an optical dipole trap and subjected to nonlinear feedback cooling. The storage protocol is realized by controlling the coupling between mechanical displacement and signal pulse by maneuvering the intensity of writing and readout pulses. The process involves writing and readout pulses at one mechanical frequency below the signal pulse. We demonstrate that during the writing pulse, a signal pulse is stored as a mechanical excitation of the nanoparticle oscillation. It is then shown that a readout pulse at later time can retrieve the stored optical information from the mechanical oscillator. A long storage lifetime of 2 ms is obtained in our system due to the absence of clamping losses. Further, we describe that our protocol can be used for wavelength conversion and shows a saturation in the conversion efficiency as a function of cooperativities of the writing and readout pulses. We also illustrate that the presence of linear feedback heating can lead to the amplification of the retrieved photon energy. Our prototype for light storage with levitated optomechanics can be used to explore the possibility of quantum memories for photonic states.
We theoretically consider light storage in a single nanoparticle levitated in an optical dipole trap and subjected to nonlinear feedback cooling. The storage protocol is realized by controlling the coupling between mechanical displacement and signal pulse by maneuvering the intensity of writing and readout pulses. The process involves writing and readout pulses at one mechanical frequency below the signal pulse. We demonstrate that during the writing pulse, a signal pulse is stored as a mechanical excitation of the nanoparticle oscillation. It is then shown that a readout pulse at later time can retrieve the stored optical information from the mechanical oscillator. A long storage lifetime of 2 ms is obtained in our system due to the absence of clamping losses. Further, we describe that our protocol can be used for wavelength conversion and shows a saturation in the conversion efficiency as a function of cooperativities of the writing and readout pulses. We also illustrate that the presence of linear feedback heating can lead to the amplification of the retrieved photon energy. Our prototype for light storage with levitated optomechanics can be used to explore the possibility of quantum memories for photonic states.
We theoretically explore a quantum memory using a single nanoparticle levitated in an optical dipole trap and subjected to feedback cooling. This protocol is realized by storing and retrieving a single-photon quantum state from a mechanical mode in levitated cavityless optomechanics. We describe the effectiveness of the photon-phonon-photon transfer in terms of the fidelity, the Wigner function, and the zero-delay second-order autocorrelation function. For experimentally accessible parameters, our numerical results indicate robust conversion of the quantum states of the input signal photon to those of the retrieved photon. We also show that high fidelity single-photon wavelength conversion is possible in the system as long as intense control pulses shorter than the mechanical damping time are used. Our work opens up the possibility of using levitated optomechanical systems for applications of quantum information processing.
We demonstrate a memory for light based on optomechanically induced transparency. We achieve a long storage time by leveraging the ultralow dissipation of a soft-clamped mechanical membrane resonator, which oscillates at MHz frequencies. At room temperature, we demonstrate a lifetime ${T}_{1}\ensuremath{\approx}23\text{ }\text{ }\mathrm{ms}$ and a retrieval efficiency $\ensuremath{\eta}\ensuremath{\approx}40%$ for classical coherent pulses. We anticipate the storage of quantum light to be possible at moderate cryogenic conditions ($T\ensuremath{\approx}10\text{ }\text{ }\mathrm{K}$). Such systems could find applications in emerging quantum networks, where they can serve as long-lived optical quantum memories by storing optical information in a phononic mode.
We demonstrate a memory for light based on optomechanically induced transparency. We achieve a long storage time by leveraging the ultra-low dissipation of a soft-clamped mechanical membrane resonator, which oscillates at MHz frequencies. At room temperature, we demonstrate a lifetime T1≈23ms and a retrieval efficiency η≈40% for classical coherent pulses. We anticipate storage of quantum light to be possible at moderate cryogenic conditions (T≈10K). Such systems could find applications in emerging quantum networks, where they can serve as long-lived optical quantum memories by storing optical information in a phononic mode.
We theoretically show that laser recoil heating in free-space levitated optomechanics can be arbitrarily suppressed by shining squeezed light onto an optically trapped nanoparticle. The presence of squeezing modifies the quantum electrodynamical light-matter interaction in a way that enables us to control the amount of information that the scattered light carries about a given mechanical degree of freedom. Moreover, we analyze the trade-off between measurement imprecision and back-action noise and show that optical detection beyond the standard quantum limit can be achieved. We predict that, with state-of-the-art squeezed light sources, laser recoil heating can be reduced by at least 60% by squeezing a single Gaussian mode with an appropriate incidence direction, and by 98% by squeezing a properly mode-matched mode. Our results, which are valid both for motional and librational degrees of freedom, will lead to improved feedback cooling schemes as well as boost the coherence time of optically levitated nanoparticles in the quantum regime.
Optically levitated nanoparticles have recently emerged as versatile platforms for investigating macroscopic quantum mechanics and enabling ultrasensitive metrology. In this paper we theoretically consider two damping regimes of an optically levitated nanoparticle cooled by cavityless parametric feedback. Our treatment is based on a generalized Fokker-Planck equation derived from the quantum master equation presented recently and shown to agree very well with experiment [B. Rodenburg, L. P. Neukirch, A. N. Vamivakas, and M. Bhattacharya, Quantum model of cooling and force sensing with an optically trapped nanoparticle, Optica 3, 318 (2016)]. For low damping, we find that the resulting Wigner function yields the single-peaked oscillator position distribution and recovers the appropriate energy distribution derived earlier using a classical theory and verified experimentally [J. Gieseler, R. Quidant, C. Dellago, and L. Novotny, Dynamic relaxation of a levitated nanoparticle from a non-equilibrium steady state, Nat. Nano. 9, 358 (2014)]. For high damping, in contrast, we predict a double-peaked position distribution, which we trace to an underlying bistability induced by feedback. Unlike in cavity-based optomechanics, stochastic processes play a major role in determining the bistable behavior. To support our conclusions, we present analytical expressions as well as numerical simulations using the truncated Wigner function approach. Our work opens up the prospect of developing bistability-based devices, characterization of phase-space dynamics, and investigation of the quantum-classical transition using levitated nanoparticles.
Optically levitated nanoparticles have recently emerged as versatile platforms for investigating macroscopic quantum mechanics and enabling ultrasensitive metrology.In this article we theoretically consider two damping regimes of an optically levitated nanoparticle cooled by cavityless parametric feedback.Our treatment is based on a generalized Fokker-Planck equation derived from the quantum master equation presented recently and shown to agree very well with experiment [1].For low damping, we find that the resulting Wigner function yields the single-peaked oscillator position distribution and recovers the appropriate energy distribution derived earlier using a classical theory and verified experimentally [2].For high damping, in contrast, we predict a double-peaked position distribution, which we trace to an underlying bistability induced by feedback.Unlike in cavitybased optomechanics, stochastic processes play a major role in determining the bistable behavior.To support our conclusions, we present analytical expressions as well as numerical simulations using the truncated Wigner function approach.Our work opens up the prospect of developing bistabilitybased devices, characterization of phase-space dynamics, and investigation of the quantum-classical transition using levitated nanoparticles.