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Bounds CC, Duff JP, Tritt A, Taylor HAM, Coe GX, White SJ, Turner LD. Quantum Spectral Analysis by Continuous Measurement of Landau-Zener Transitions. PHYSICAL REVIEW LETTERS 2024; 132:093401. [PMID: 38489644 DOI: 10.1103/physrevlett.132.093401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 01/17/2024] [Indexed: 03/17/2024]
Abstract
We demonstrate the simultaneous estimation of signal frequency and amplitude by a single quantum sensor in a single experimental shot. Sweeping the qubit splitting linearly across a span of frequencies induces a nonadiabatic Landau-Zener transition as the qubit crosses resonance. The signal frequency determines the time of the transition, and the amplitude its extent. Continuous weak measurement of this unitary evolution informs a parameter estimator retrieving precision measurements of frequency and amplitude. Implemented on radio-frequency-dressed ultracold atoms read out by a Faraday spin-light interface, we sense a magnetic signal with estimated sensitivities to amplitude of 11 pT/sqrt[Hz], frequency 0.026 Hz/Hz^{3/2}, and phase 0.084 rad/sqrt[Hz], in a single 300 ms sweep from 7 to 13 kHz. The protocol realizes a swept-sine quantum spectrum analyzer, potentially sensing hundreds or thousands of channels with a single quantum sensor.
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Affiliation(s)
- Christopher C Bounds
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - Josh P Duff
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - Alex Tritt
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - Hamish A M Taylor
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - George X Coe
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - Sam J White
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
| | - L D Turner
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
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2
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Hofmann C, Bray A, Koch W, Ni H, Shvetsov-Shilovski NI. Quantum battles in attoscience: tunnelling. THE EUROPEAN PHYSICAL JOURNAL. D, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2021; 75:208. [PMID: 34720729 PMCID: PMC8550434 DOI: 10.1140/epjd/s10053-021-00224-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/06/2021] [Indexed: 05/29/2023]
Abstract
ABSTRACT What is the nature of tunnelling? This yet unanswered question is as pertinent today as it was at the dawn of quantum mechanics. This article presents a cross section of current perspectives on the interpretation, computational modelling, and numerical investigation of tunnelling processes in attosecond physics as debated in the Quantum Battles in Attoscience virtual workshop 2020. GRAPHIC ABSTRACT
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Affiliation(s)
- Cornelia Hofmann
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
| | - Alexander Bray
- Research School of Physics, The Australian National University, Canberra, ACT 0200 Australia
| | - Werner Koch
- Weizmann Institute of Science, Rehovot, Israel
| | - Hongcheng Ni
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241 China
- Institute for Theoretical Physics, Vienna University of Technology, 1040 Vienna, Austria
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3
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Topological features without a lattice in Rashba spin-orbit coupled atoms. Nat Commun 2021; 12:593. [PMID: 33500408 PMCID: PMC7838279 DOI: 10.1038/s41467-020-20762-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 12/18/2020] [Indexed: 11/08/2022] Open
Abstract
Topological order can be found in a wide range of physical systems, from crystalline solids, photonic meta-materials and even atmospheric waves to optomechanic, acoustic and atomic systems. Topological systems are a robust foundation for creating quantized channels for transporting electrical current, light, and atmospheric disturbances. These topological effects are quantified in terms of integer-valued 'invariants', such as the Chern number, applicable to the quantum Hall effect, or the [Formula: see text] invariant suitable for topological insulators. Here, we report the engineering of Rashba spin-orbit coupling for a cold atomic gas giving non-trivial topology, without the underlying crystalline structure that conventionally yields integer Chern numbers. We validated our procedure by spectroscopically measuring both branches of the Rashba dispersion relation which touch at a single Dirac point. We then measured the quantum geometry underlying the dispersion relation using matter-wave interferometry to implement a form of quantum state tomography, giving a Berry's phase with magnitude π. This implies that opening a gap at the Dirac point would give two dispersions (bands) each with half-integer Chern number, potentially implying new forms of topological transport.
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Barker DS, Restelli A, Fedchak JA, Scherschligt J, Eckel S. A radiofrequency voltage-controlled current source for quantum spin manipulation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:104708. [PMID: 33138586 DOI: 10.1063/5.0011813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
We present a wide-bandwidth, voltage-controlled current source that is easily integrated with radiofrequency magnetic field coils. Our design uses current feedback to compensate for the frequency-dependent impedance of a radiofrequency antenna. We are able to deliver peak currents greater than 100 mA over a 300 kHz to 54 MHz frequency span. The radiofrequency current source fits onto a printed circuit board smaller than 4 cm2 and consumes less than 1.3 W of power. It is suitable for use in deployable quantum sensors and nuclear magnetic resonance systems.
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Affiliation(s)
- D S Barker
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - A Restelli
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - J A Fedchak
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J Scherschligt
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - S Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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5
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Farolfi A, Trypogeorgos D, Mordini C, Lamporesi G, Ferrari G. Observation of Magnetic Solitons in Two-Component Bose-Einstein Condensates. PHYSICAL REVIEW LETTERS 2020; 125:030401. [PMID: 32745386 DOI: 10.1103/physrevlett.125.030401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/11/2020] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
We experimentally investigate the dynamics of spin solitary waves (magnetic solitons) in a harmonically trapped, binary superfluid mixture. We measure the in situ density of each pseudospin component and their relative local phase via an interferometric technique we developed and as such, fully characterize the magnetic solitons while they undergo oscillatory motion in the trap. Magnetic solitons exhibit nondispersive, dissipationless longtime dynamics. By imprinting multiple magnetic solitons in our ultracold gas sample, we engineer binary collisions between solitons of either the same or opposite magnetization and map out their trajectories.
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Affiliation(s)
- A Farolfi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - D Trypogeorgos
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - C Mordini
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
| | - G Ferrari
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
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Anderson RP, Trypogeorgos D, Valdés-Curiel A, Liang QY, Tao J, Zhao M, Andrijauskas T, Juzeliūnas G, Spielman IB. Realization of a deeply subwavelength adiabatic optical lattice. PHYSICAL REVIEW RESEARCH 2020; 2:10.1103/physrevresearch.2.013149. [PMID: 34796336 PMCID: PMC8596489 DOI: 10.1103/physrevresearch.2.013149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We propose and describe our realization of a deeply subwavelength optical lattice for ultracold neutral atoms using N resonantly Raman-coupled internal degrees of freedom. Although counterpropagating lasers with wavelength λ provided two-photon Raman coupling, the resultant lattice period was λ/2N, an N-fold reduction as compared to the conventional λ/2 lattice period. We experimentally demonstrated this lattice built from the three F = 1 Zeeman states of a 87Rb Bose-Einstein condensate, and generated a lattice with a λ/6 = 132 nm period from λ = 790 nm lasers. Lastly, we show that adding an additional rf-coupling field converts this lattice into a superlattice with N wells uniformly spaced within the original λ/2 unit cell.
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Affiliation(s)
- R. P. Anderson
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800, Australia
- La Trobe Institute of Molecular Science, La Trobe University, Bendigo, Victoria 3552, Australia
| | - D. Trypogeorgos
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - A. Valdés-Curiel
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - Q.-Y. Liang
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - J. Tao
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - M. Zhao
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
| | - T. Andrijauskas
- Institute of Theoretical Physics and Astronomy, Vilnius University, Saulėtekio 3, LT-10257 Vilnius, Lithuania
| | - G. Juzeliūnas
- Institute of Theoretical Physics and Astronomy, Vilnius University, Saulėtekio 3, LT-10257 Vilnius, Lithuania
| | - I. B. Spielman
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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7
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Farolfi A, Trypogeorgos D, Colzi G, Fava E, Lamporesi G, Ferrari G. Design and characterization of a compact magnetic shield for ultracold atomic gas experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:115114. [PMID: 31779406 DOI: 10.1063/1.5119915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
We report on the design, construction, and performance of a compact magnetic shield that facilitates a controlled, low-noise environment for experiments with ultracold atomic gases. The shield was designed to passively attenuate external slowly varying magnetic fields while allowing for ample optical access. The geometry, number of layers, and choice of materials were optimized using extensive finite-element numerical simulations. The measured performance of the shield is in good agreement with the simulations. From measurements of the spin coherence of an ultracold atomic ensemble, we demonstrate a residual field noise of 2.6 μG and a suppression of external dc magnetic fields by more than five orders of magnitude.
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Affiliation(s)
- A Farolfi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - D Trypogeorgos
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - G Colzi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - E Fava
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - G Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
| | - G Ferrari
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy
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8
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Stark A, Aharon N, Huck A, El-Ella HAR, Retzker A, Jelezko F, Andersen UL. Clock transition by continuous dynamical decoupling of a three-level system. Sci Rep 2018; 8:14807. [PMID: 30287884 PMCID: PMC6172288 DOI: 10.1038/s41598-018-31984-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/28/2018] [Indexed: 11/09/2022] Open
Abstract
We present a novel continuous dynamical decoupling scheme for the construction of a robust qubit in a three-level system. By means of a clock transition adjustment, we first show how robustness to environmental noise is achieved, while eliminating drive-noise, to first-order. We demonstrate this scheme with the spin sub-levels of the NV-centre's electronic ground state. By applying drive fields with moderate Rabi frequencies, the drive noise is eliminated and an improvement of 2 orders of magnitude in the coherence time is obtained compared to the pure dephasing time. We then show how the clock transition adjustment can be tuned to eliminate also the second-order effect of the environmental noise with moderate drive fields. A further detailed theoretical investigation suggests an additional improvement of more than 1 order of magnitude in the coherence time which is supported by simulations. Hence, our scheme predicts that the coherence time may be prolonged towards the lifetime-limit using a relatively simple experimental setup.
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Affiliation(s)
- Alexander Stark
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, Ulm, 89081, Germany.
| | - Nati Aharon
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Alexander Huck
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Haitham A R El-Ella
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Alex Retzker
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Fedor Jelezko
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, Ulm, 89081, Germany
- Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm, 89081, Germany
| | - Ulrik L Andersen
- Center for Macroscopic Quantum States (bigQ), Department of Physics, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
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9
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Chen HR, Lin KY, Chen PK, Chiu NC, Wang JB, Chen CA, Huang PP, Yip SK, Kawaguchi Y, Lin YJ. Spin-Orbital-Angular-Momentum Coupled Bose-Einstein Condensates. PHYSICAL REVIEW LETTERS 2018; 121:113204. [PMID: 30265085 DOI: 10.1103/physrevlett.121.113204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate coupling between the atomic spin- and orbital-angular momentum (OAM) of the atom's center-of-mass motion in a Bose-Einstein condensate (BEC). The coupling is induced by Raman-dressing lasers with a Laguerre-Gaussian beam and creates coreless vortices in an F=1 ^{87}Rb spinor BEC. We observe correlations between spin and OAM in the dressed state and characterize the spin texture; the result is in good agreement with the theory. In the presence of the Raman field, our dressed state is stable for 0.1 s or longer, and it decays due to collision-induced relaxation. As we turn off the Raman beams, the vortex cores in the bare spin |m_{F}=1⟩ and |-1⟩ split. These spin-OAM coupled systems with the Raman-dressing approach have great potential for exploring new topological textures and quantum states.
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Affiliation(s)
- H-R Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - K-Y Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - P-K Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - N-C Chiu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - J-B Wang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - C-A Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - P-P Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - S-K Yip
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Yuki Kawaguchi
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Y-J Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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Trypogeorgos D, Valdés-Curiel A, Spielman IB, Emary C. Perpetual emulation threshold of P T -symmetric Hamiltonians. JOURNAL OF PHYSICS. A, MATHEMATICAL AND THEORETICAL 2018; 51:10.1088/1751-8121/aacc5e. [PMID: 30996732 PMCID: PMC6463308 DOI: 10.1088/1751-8121/aacc5e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We describe a technique to emulate the dynamics of two-level P T -symmetric spin Hamiltonians, replete with gain and loss, using the unitary dynamics of a larger quantum system. The two-level system in question is embedded in a subspace of a four-level Hamiltonian, with the exterior levels acting as reservoirs. The emulation time is normally finite, limited by the depletion of the reservoirs. We show that it is possible to emulate the desired behaviour of the P T -symmetric Hamiltonian without depleting the reservoir levels, by including an additional coupling between them. This extends the emulation time indefinitely, when in the unbroken symmetry phase of the non-unitary P T dynamics. We propose a realistic experimental implementation using dynamically decoupled magnetic sublevels of ultracold atoms.
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Affiliation(s)
- D Trypogeorgos
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, United States of America
| | - A Valdés-Curiel
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, United States of America
| | - I B Spielman
- Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, United States of America
| | - C Emary
- Joint Quantum Centre Durham-Newcastle, School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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