1
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Bærentsen C, Fedorov SA, Østfeldt C, Balabas MV, Zeuthen E, Polzik ES. Squeezed light from an oscillator measured at the rate of oscillation. Nat Commun 2024; 15:4146. [PMID: 38755123 PMCID: PMC11099115 DOI: 10.1038/s41467-024-47906-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 04/15/2024] [Indexed: 05/18/2024] Open
Abstract
Sufficiently fast continuous measurements of the position of an oscillator approach measurements projective on position eigenstates. We evidence the transition into the projective regime for a spin oscillator within an ensemble of 2 × 1010 room-temperature atoms by observing correlations between the quadratures of the meter light field. These correlations squeeze the fluctuations of one light quadrature below the vacuum level. When the measurement is slower than the oscillation, we generate 11 . 5 - 1.5 + 2.5 dB and detect 8 . 5 - 0.1 + 0.1 dB of squeezing in a tunable band that is a fraction of the resonance frequency. When the measurement is as fast as the oscillation, we detect 4.7 dB of squeezing that spans more than one decade of frequencies below the resonance. Our results demonstrate a new regime of continuous quantum measurements on material oscillators, and set a new benchmark for the performance of a linear quantum sensor.
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Affiliation(s)
| | - Sergey A Fedorov
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | | | | | - Emil Zeuthen
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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2
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Clarke J, Neveu P, Khosla KE, Verhagen E, Vanner MR. Cavity Quantum Optomechanical Nonlinearities and Position Measurement beyond the Breakdown of the Linearized Approximation. PHYSICAL REVIEW LETTERS 2023; 131:053601. [PMID: 37595248 DOI: 10.1103/physrevlett.131.053601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 05/05/2023] [Accepted: 06/28/2023] [Indexed: 08/20/2023]
Abstract
Several optomechanics experiments are now entering the highly sought nonlinear regime where optomechanical interactions are large even for low light levels. Within this regime, new quantum phenomena and improved performance may be achieved; however, a corresponding theoretical formalism of cavity quantum optomechanics that captures the nonlinearities of both the radiation-pressure interaction and the cavity response is needed to unlock these capabilities. Here, we develop such a nonlinear cavity quantum optomechanical framework, which we then utilize to propose how position measurement can be performed beyond the breakdown of the linearized approximation. Our proposal utilizes optical general-dyne detection, ranging from single to dual homodyne, to obtain mechanical position information imprinted onto both the optical amplitude and phase quadratures and enables both pulsed and continuous modes of operation. These cavity optomechanical nonlinearities are now being confronted in a growing number of experiments, and our framework will allow a range of advances to be made in, e.g., quantum metrology, explorations of the standard quantum limit, and quantum measurement and control.
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Affiliation(s)
- J Clarke
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
| | - P Neveu
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - K E Khosla
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
| | - E Verhagen
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - M R Vanner
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
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3
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Navarathna A, Bennett JS, Bowen WP. Continuous Optical-to-Mechanical Quantum State Transfer in the Unresolved Sideband Regime. PHYSICAL REVIEW LETTERS 2023; 130:263603. [PMID: 37450795 DOI: 10.1103/physrevlett.130.263603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 06/08/2023] [Indexed: 07/18/2023]
Abstract
Optical-to-mechanical quantum state transfer is an important capability for future quantum networks, quantum communication, and distributed quantum sensing. However, existing continuous state transfer protocols operate in the resolved sideband regime, necessitating a high-quality optical cavity and a high mechanical resonance frequency. Here, we propose a continuous protocol that operates in the unresolved sideband regime. The protocol is based on feedback cooling, can be implemented with current technology, and is able to transfer non-Gaussian quantum states with high fidelity. Our protocol significantly expands the kinds of optomechanical devices for which continuous optical-to-mechanical state transfer is possible, paving the way toward quantum technological applications and the preparation of macroscopic superpositions to test the fundamentals of quantum science.
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Affiliation(s)
- Amy Navarathna
- ARC Centre of Excellence for Engineered Quantum Systems, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland 4072, Australia
| | - James S Bennett
- ARC Centre of Excellence for Engineered Quantum Systems, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland 4072, Australia
- Centre for Quantum Dynamics, Griffith University, Nathan, Queensland 4222, Australia
| | - Warwick P Bowen
- ARC Centre of Excellence for Engineered Quantum Systems, St Lucia, Queensland 4072, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland 4072, Australia
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4
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Zheng W, Wang H, Schmieg R, Oesterle A, Polzik ES. Entanglement-Enhanced Magnetic Induction Tomography. PHYSICAL REVIEW LETTERS 2023; 130:203602. [PMID: 37267567 DOI: 10.1103/physrevlett.130.203602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 04/04/2023] [Indexed: 06/04/2023]
Abstract
Magnetic induction tomography (MIT) is a sensing protocol exploring conductive objects via their response to radio-frequency magnetic fields. MIT is used in nondestructive testing ranging from geophysics to medical applications. Atomic magnetometers, employed as MIT sensors, allow for significant improvement of the MIT sensitivity and for exploring its quantum limits. Here, we propose and verify a quantum-enhanced version of the atomic MIT by combining it with conditional spin squeezing and stroboscopic backaction evasion. We use this quantum enhancement to demonstrate sensitivity beyond the standard quantum limits of one-dimensional quantum MIT detecting a conductive sample.
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Affiliation(s)
- Wenqiang Zheng
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen ø, Denmark
- Zhejiang Provincial Key Laboratory and Collaborative Innovation Center for Quantum Precision Measurement, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
| | - Hengyan Wang
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen ø, Denmark
- Department of Physics, Zhejiang University of Science and Technology, Hangzhou 310023, China
| | - Rebecca Schmieg
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen ø, Denmark
| | - Alan Oesterle
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen ø, Denmark
| | - Eugene S Polzik
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen ø, Denmark
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5
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Enzian G, Wang Z, Simonsen A, Mathiassen J, Vibel T, Tsaturyan Y, Tagantsev A, Schliesser A, Polzik ES. Phononically shielded photonic-crystal mirror membranes for cavity quantum optomechanics. OPTICS EXPRESS 2023; 31:13040-13052. [PMID: 37157450 DOI: 10.1364/oe.484369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We present a highly reflective, sub-wavelength-thick membrane resonator featuring high mechanical quality factor and discuss its applicability for cavity optomechanics. The 88.5 nm thin stoichiometric silicon-nitride membrane, designed and fabricated to combine 2D-photonic and phononic crystal patterns, reaches reflectivities up to 99.89 % and a mechanical quality factor of 2.9 × 107 at room temperature. We construct a Fabry-Perot-type optical cavity, with the membrane forming one terminating mirror. The optical beam shape in cavity transmission shows a stark deviation from a simple Gaussian mode-shape, consistent with theoretical predictions. We demonstrate optomechanical sideband cooling to mK-mode temperatures, starting from room temperature. At higher intracavity powers we observe an optomechanically induced optical bistability. The demonstrated device has potential to reach high cooperativities at low light levels desirable, for example, for optomechanical sensing and squeezing applications or fundamental studies in cavity quantum optomechanics; and meets the requirements for cooling to the quantum ground state of mechanical motion from room temperature.
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6
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Ruppert L, Rakhubovsky A, Filip R. High-precision multiparameter estimation of mechanical force by quantum optomechanics. Sci Rep 2022; 12:16022. [PMID: 36163483 PMCID: PMC9512796 DOI: 10.1038/s41598-022-20150-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 09/09/2022] [Indexed: 11/30/2022] Open
Abstract
A nanomechanical oscillator can be used as a sensitive probe of a small linearized mechanical force. We propose a simple quantum optomechanical scheme using a coherent light mode in the cavity and weak short-pulsed light-matter interactions. Our main result is that if we transfer some displacement to the mechanical mode in an initialization phase, then a much weaker optomechanical interaction is enough to obtain a high-precision multiparameter estimation of the unknown force. This approach includes not only estimating the displacement caused by the force but also simultaneously observing the phase shift and squeezing of the mechanical mode. We show that the proposed scheme is robust against typical experimental imperfections and demonstrate the feasibility of our scheme using orders of magnitude weaker optomechanical interactions than in previous related works. Thus, we present a simple, robust estimation scheme requiring only very weak light-matter interactions, which could open the way to new nanomechanical sensors.
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Affiliation(s)
- László Ruppert
- Department of Optics, Palacky University, 17. listopadu 12, 77 146, Olomouc, Czech Republic.
| | - Andrey Rakhubovsky
- Department of Optics, Palacky University, 17. listopadu 12, 77 146, Olomouc, Czech Republic
| | - Radim Filip
- Department of Optics, Palacky University, 17. listopadu 12, 77 146, Olomouc, Czech Republic
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7
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Meng C, Brawley GA, Khademi S, Bridge EM, Bennett JS, Bowen WP. Measurement-based preparation of multimode mechanical states. SCIENCE ADVANCES 2022; 8:eabm7585. [PMID: 35622924 PMCID: PMC9140969 DOI: 10.1126/sciadv.abm7585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
Nanomechanical resonators are a key tool for future quantum technologies, such as quantum force sensors and interfaces, and for studies of macroscopic quantum physics. The ability to prepare room temperature nonclassical states is a major outstanding challenge. It has been suggested that this could be achieved using a fast continuous measurement to break the usual symmetry between position and momentum. Here, we demonstrate this symmetry breaking and use it to prepare a thermally squeezed mechanical state. Our experiments take advantage of collective measurements on multiple mechanical modes, which we show can increase the measurement speed and improve state preparation. Theoretically, we show that this result extends to the quantum regime, relaxing the requirements to generate nonclassical states. We predict that multimode conditioning can enable room temperature quantum squeezing with existing technology. Our work paves the way toward room temperature quantum nanomechanical devices and toward their application in quantum technology and fundamental science.
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Affiliation(s)
- Chao Meng
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - George A. Brawley
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
- Terra15 Technologies Pty Ltd., Level 9/256 Adelaide Terrace, Perth, Western Australia 6000, Australia
| | - Soroush Khademi
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Elizabeth M. Bridge
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - James S. Bennett
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Warwick P. Bowen
- Australian Research Council Centre of Excellence for Engineered Quantum Systems, School of Mathematics and Physics, The University of Queensland, St Lucia, Queensland 4072, Australia
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8
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Kustura K, Gonzalez-Ballestero C, Sommer ADLR, Meyer N, Quidant R, Romero-Isart O. Mechanical Squeezing via Unstable Dynamics in a Microcavity. PHYSICAL REVIEW LETTERS 2022; 128:143601. [PMID: 35476467 DOI: 10.1103/physrevlett.128.143601] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
We theoretically show that strong mechanical quantum squeezing in a linear optomechanical system can be rapidly generated through the dynamical instability reached in the far red-detuned and ultrastrong coupling regime. We show that this mechanism, which harnesses unstable multimode quantum dynamics, is particularly suited to levitated optomechanics, and we argue for its feasibility for the case of a levitated nanoparticle coupled to a microcavity via coherent scattering. We predict that for submillimeter-sized cavities the particle motion, initially thermal and well above its ground state, becomes mechanically squeezed by tens of decibels on a microsecond timescale. Our results bring forth optical microcavities in the unresolved sideband regime as powerful mechanical squeezers for levitated nanoparticles, and hence as key tools for quantum-enhanced inertial and force sensing.
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Affiliation(s)
- Katja Kustura
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Carlos Gonzalez-Ballestero
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Andrés de Los Ríos Sommer
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
- Quantum Center, ETH Zurich, 8083 Zurich, Switzerland
| | - Nadine Meyer
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
- Quantum Center, ETH Zurich, 8083 Zurich, Switzerland
| | - Romain Quidant
- Nanophotonic Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
- Quantum Center, ETH Zurich, 8083 Zurich, Switzerland
| | - Oriol Romero-Isart
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria
- Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria
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9
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Lipka M, Parniak M. Single-Photon Hologram of a Zero-Area Pulse. PHYSICAL REVIEW LETTERS 2021; 127:163601. [PMID: 34723616 DOI: 10.1103/physrevlett.127.163601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
Single photons exhibit inherently quantum and unintuitive properties such as the Hong-Ou-Mandel effect, demonstrating their bosonic and quantized nature, yet at the same time may correspond to single excitations of spatial or temporal modes with a very complex structure. Those two features are rarely seen together. Here we experimentally demonstrate how the Hong-Ou-Mandel effect can be spectrally resolved and harnessed to characterize a complex temporal mode of a single-photon-a zero-area pulse-obtained via a resonant interaction of a terahertz-bandwidth photon with a narrow gigahertz-wide atomic transition of atomic vapor. The combination of bosonic quantum behavior with bandwidth-mismatched light-atom interaction is of fundamental importance for deeper understanding of both phenomena, as well as their engineering offering applications in characterization of ultrafast transient processes.
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Affiliation(s)
- Michał Lipka
- Centre for Quantum Optical Technologies, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Michał Parniak
- Centre for Quantum Optical Technologies, Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
- Niels Bohr Institute, University of Copanhagen, Blegdamsvej 17, 2100 Copenhagen, Denmark
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10
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Tebbenjohanns F, Mattana ML, Rossi M, Frimmer M, Novotny L. Quantum control of a nanoparticle optically levitated in cryogenic free space. Nature 2021; 595:378-382. [PMID: 34262214 DOI: 10.1038/s41586-021-03617-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/05/2021] [Indexed: 02/06/2023]
Abstract
Tests of quantum mechanics on a macroscopic scale require extreme control over mechanical motion and its decoherence1-3. Quantum control of mechanical motion has been achieved by engineering the radiation-pressure coupling between a micromechanical oscillator and the electromagnetic field in a resonator4-7. Furthermore, measurement-based feedback control relying on cavity-enhanced detection schemes has been used to cool micromechanical oscillators to their quantum ground states8. In contrast to mechanically tethered systems, optically levitated nanoparticles are particularly promising candidates for matter-wave experiments with massive objects9,10, since their trapping potential is fully controllable. Here we optically levitate a femtogram (10-15 grams) dielectric particle in cryogenic free space, which suppresses thermal effects sufficiently to make the measurement backaction the dominant decoherence mechanism. With an efficient quantum measurement, we exert quantum control over the dynamics of the particle. We cool its centre-of-mass motion by measurement-based feedback to an average occupancy of 0.65 motional quanta, corresponding to a state purity of 0.43. The absence of an optical resonator and its bandwidth limitations holds promise to transfer the full quantum control available for electromagnetic fields to a mechanical system. Together with the fact that the optical trapping potential is highly controllable, our experimental platform offers a route to investigating quantum mechanics at macroscopic scales11.
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Affiliation(s)
| | | | | | | | - Lukas Novotny
- Photonics Laboratory, ETH Zürich, Zürich, Switzerland. .,Quantum Center, ETH Zurich, Zürich, Switzerland.
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