1
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Zhang C, Rittenhouse ST, Tscherbul TV, Sadeghpour HR, Hutzler NR. Sympathetic Cooling and Slowing of Molecules with Rydberg Atoms. PHYSICAL REVIEW LETTERS 2024; 132:033001. [PMID: 38307061 DOI: 10.1103/physrevlett.132.033001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/05/2023] [Indexed: 02/04/2024]
Abstract
We propose to sympathetically slow and cool polar molecules in a cold, low-density beam using laser-cooled Rydberg atoms. The elastic collision cross sections between molecules and Rydberg atoms are large enough to efficiently thermalize the molecules even in a low-density environment. Molecules traveling at 100 m/s can be stopped in under 30 collisions with little inelastic loss. Our method does not require photon scattering from the molecules and can be generically applied to complex species for applications in precision measurement, quantum information science, and controlled chemistry.
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Affiliation(s)
- Chi Zhang
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Seth T Rittenhouse
- Department of Physics, the United States Naval Academy, Annapolis, Maryland 21402, USA
- ITAMP, Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, USA
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
| | - H R Sadeghpour
- ITAMP, Center for Astrophysics | Harvard & Smithsonian Cambridge, Massachusetts 02138, USA
| | - Nicholas R Hutzler
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
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2
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Zhang C, Yu P, Jadbabaie A, Hutzler NR. Quantum-Enhanced Metrology for Molecular Symmetry Violation Using Decoherence-Free Subspaces. PHYSICAL REVIEW LETTERS 2023; 131:193602. [PMID: 38000409 DOI: 10.1103/physrevlett.131.193602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 10/12/2023] [Indexed: 11/26/2023]
Abstract
We propose a method to measure time-reversal symmetry violation in molecules that overcomes the standard quantum limit while leveraging decoherence-free subspaces to mitigate sensitivity to classical noise. The protocol does not require an external electric field, and the entangled states have no first-order sensitivity to static electromagnetic fields as they involve superpositions with zero average lab-frame projection of spins and dipoles. This protocol can be applied with trapped neutral or ionic species, and can be implemented using methods that have been demonstrated experimentally.
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Affiliation(s)
- Chi Zhang
- California Institute of Technology, Division of Physics, Mathematics, and Astronomy, Pasadena, California 91125, USA
| | - Phelan Yu
- California Institute of Technology, Division of Physics, Mathematics, and Astronomy, Pasadena, California 91125, USA
| | - Arian Jadbabaie
- California Institute of Technology, Division of Physics, Mathematics, and Astronomy, Pasadena, California 91125, USA
| | - Nicholas R Hutzler
- California Institute of Technology, Division of Physics, Mathematics, and Astronomy, Pasadena, California 91125, USA
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3
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Park AJ, Picard LRB, Patenotte GE, Zhang JT, Rosenband T, Ni KK. Extended Rotational Coherence of Polar Molecules in an Elliptically Polarized Trap. PHYSICAL REVIEW LETTERS 2023; 131:183401. [PMID: 37977633 DOI: 10.1103/physrevlett.131.183401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 09/02/2023] [Accepted: 09/25/2023] [Indexed: 11/19/2023]
Abstract
We demonstrate long rotational coherence of individual polar molecules in the motional ground state of an optical trap. In the present, previously unexplored regime, the rotational eigenstates of molecules are dominantly quantized by trapping light rather than static fields, and the main source of decoherence is differential light shift. In an optical tweezer array of NaCs molecules, we achieve a three-orders-of-magnitude reduction in differential light shift by changing the trap's polarization from linear to a specific "magic" ellipticity. With spin-echo pulses, we measure a rotational coherence time of 62(3) ms (one pulse) and 250(40) ms (up to 72 pulses), surpassing the projected duration of resonant dipole-dipole entangling gates by orders of magnitude.
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Affiliation(s)
- Annie J Park
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Lewis R B Picard
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Gabriel E Patenotte
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Jessie T Zhang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | | | - Kang-Kuen Ni
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
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4
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Bigagli N, Savin DW, Will S. Laser Scheme for Doppler Cooling of the Hydroxyl Cation (OH +). J Phys Chem A 2023; 127:8194-8199. [PMID: 37738380 DOI: 10.1021/acs.jpca.3c03248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
We report on a cycling scheme for Doppler cooling of trapped OH+ ions using transitions between the electronic ground state X3Σ- and the first excited triplet state A3Π. We have identified relevant transitions for photon cycling and repumping, have found that coupling into other electronic states is strongly suppressed, and have calculated the number of photon scatterings required to cool OH+ to a temperature where Raman sideband cooling can take over. In contrast to the standard approach, where molecular ions are sympathetically cooled, our scheme does not require co-trapping of another species and opens the door to the creation of pure samples of cold molecular ions with potential applications in quantum information, quantum chemistry, and astrochemistry. The laser cooling scheme identified for OH+ is efficient despite the absence of near-diagonal Franck-Condon factors, suggesting that broader classes of molecules and molecular ions are amenable to laser cooling than commonly assumed.
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Affiliation(s)
- Niccolò Bigagli
- Department of Physics, Columbia University, New York, New York 10027, United States
| | - Daniel W Savin
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, United States
| | - Sebastian Will
- Department of Physics, Columbia University, New York, New York 10027, United States
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5
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Asnaashari K, Krems RV, Tscherbul TV. General Classification of Qubit Encodings in Ultracold Diatomic Molecules. J Phys Chem A 2023; 127:6593-6602. [PMID: 37494464 DOI: 10.1021/acs.jpca.3c02835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Owing to their rich internal structure and significant long-range interactions, ultracold molecules have been widely explored as carriers of quantum information. Several different schemes for encoding qubits into molecular states, both bare and field-dressed, have been proposed. At the same time, the rich internal structure of molecules leaves many unexplored possibilities for qubit encodings. We show that all molecular qubit encodings can be classified into four classes by the type of the effective interaction between the qubits. In the case of polar molecules, the four classes are determined by the relative magnitudes of matrix elements of the dipole moment operator in the single-molecule basis. We exemplify our classification scheme by considering the encoding of the effective spin-1/2 system into nonadjacent rotational states (e.g., N = 0 and 2) of polar and nonpolar molecules with the same nuclear spin projection. Our classification scheme is designed to inform the optimal choice of molecular qubit encoding for quantum information storage and processing applications, as well as for dynamical generation of many-body entangled states and for quantum annealing.
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Affiliation(s)
- Kasra Asnaashari
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Roman V Krems
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, United States
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6
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Guttridge A, Ruttley DK, Baldock AC, González-Férez R, Sadeghpour HR, Adams CS, Cornish SL. Observation of Rydberg Blockade Due to the Charge-Dipole Interaction between an Atom and a Polar Molecule. PHYSICAL REVIEW LETTERS 2023; 131:013401. [PMID: 37478436 DOI: 10.1103/physrevlett.131.013401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/15/2023] [Indexed: 07/23/2023]
Abstract
We demonstrate Rydberg blockade due to the charge-dipole interaction between a single Rb atom and a single RbCs molecule confined in optical tweezers. The molecule is formed by magnetoassociation of a Rb+Cs atom pair and subsequently transferred to the rovibrational ground state with an efficiency of 91(1)%. Species-specific tweezers are used to control the separation between the atom and molecule. The charge-dipole interaction causes blockade of the transition to the Rb(52s) Rydberg state, when the atom-molecule separation is set to 310(40) nm. The observed excitation dynamics are in good agreement with simulations using calculated interaction potentials. Our results open up the prospect of a hybrid platform where quantum information is transferred between individually trapped molecules using Rydberg atoms.
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Affiliation(s)
- Alexander Guttridge
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
- Joint Quantum Centre Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Daniel K Ruttley
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
- Joint Quantum Centre Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Archie C Baldock
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Rosario González-Férez
- Instituto Carlos I de Física Teórica y Computacional, and Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada, Spain
| | - H R Sadeghpour
- ITAMP, Center for Astrophysics | Harvard & Smithsonian, Cambridge, Massachusetts 02138, USA
| | - C S Adams
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
- Joint Quantum Centre Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Simon L Cornish
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
- Joint Quantum Centre Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
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7
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Tscherbul TV, Ye J, Rey AM. Robust Nuclear Spin Entanglement via Dipolar Interactions in Polar Molecules. PHYSICAL REVIEW LETTERS 2023; 130:143002. [PMID: 37084438 DOI: 10.1103/physrevlett.130.143002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 03/13/2023] [Indexed: 05/03/2023]
Abstract
We propose a general protocol for on-demand generation of robust entangled states of nuclear and/or electron spins of ultracold ^{1}Σ and ^{2}Σ polar molecules using electric dipolar interactions. By encoding a spin-1/2 degree of freedom in a combined set of spin and rotational molecular levels, we theoretically demonstrate the emergence of effective spin-spin interactions of the Ising and XXZ forms, enabled by efficient magnetic control over electric dipolar interactions. We show how to use these interactions to create long-lived cluster and squeezed spin states.
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Affiliation(s)
- Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
| | - Jun Ye
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Ana Maria Rey
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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8
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Karman T. Resonances in Non-universal Dipolar Collisions. J Phys Chem A 2023; 127:2194-2211. [PMID: 36825902 PMCID: PMC10009814 DOI: 10.1021/acs.jpca.3c00797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Scattering resonances due to the dipole-dipole interaction between ultracold molecules, induced by static or microwave fields, are studied theoretically. We develop a method for coupled-channel calculations that can efficiently impose many short-range boundary conditions, defined by a short-range phase shift and loss probability as in quantum defect theory. We study how resonances appear as the short-range loss probability is lowered below the universal unit probability. This may become realizable for nonreactive ultracold molecules in blue-detuned box potentials.
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Affiliation(s)
- Tijs Karman
- Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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9
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Christakis L, Rosenberg JS, Raj R, Chi S, Morningstar A, Huse DA, Yan ZZ, Bakr WS. Probing site-resolved correlations in a spin system of ultracold molecules. Nature 2023; 614:64-69. [PMID: 36725998 DOI: 10.1038/s41586-022-05558-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/11/2022] [Indexed: 02/03/2023]
Abstract
Synthetic quantum systems with interacting constituents play an important role in quantum information processing and in explaining fundamental phenomena in many-body physics. Following impressive advances in cooling and trapping techniques, ensembles of ultracold polar molecules have emerged as a promising platform that combines several advantageous properties1-11. These include a large set of internal states with long coherence times12-17 and long-range, anisotropic interactions. These features could enable the exploration of intriguing phases of correlated quantum matter, such as topological superfluids18, quantum spin liquids19, fractional Chern insulators20 and quantum magnets21,22. Probing correlations in these phases is crucial to understanding their properties, necessitating the development of new experimental techniques. Here we use quantum gas microscopy23 to measure the site-resolved dynamics of quantum correlations of polar 23Na87Rb molecules confined in a two-dimensional optical lattice. By using two rotational states of the molecules, we realize a spin-1/2 system with dipolar interactions between particles, producing a quantum spin-exchange model21,22,24,25. We study the evolution of correlations during the thermalization process of an out-of-equilibrium spin system for both spatially isotropic and anisotropic interactions. Furthermore, we examine the correlation dynamics of a spin-anisotropic Heisenberg model engineered from the native spin-exchange model by using periodic microwave pulses26-28. These experiments push the frontier of probing and controlling interacting systems of ultracold molecules, with prospects for exploring new regimes of quantum matter and characterizing entangled states that are useful for quantum computation29,30 and metrology31.
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Affiliation(s)
| | | | - Ravin Raj
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Sungjae Chi
- Department of Physics, Princeton University, Princeton, NJ, USA
| | | | - David A Huse
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Zoe Z Yan
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Waseem S Bakr
- Department of Physics, Princeton University, Princeton, NJ, USA.
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10
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Li JF, Hu JR, Guo QF, He DS. Resonant and non-resonant optimizations by multi-constraint quantum control theory in molecular rotational states. Sci Rep 2022; 12:19210. [DOI: 10.1038/s41598-022-23762-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/04/2022] [Indexed: 11/12/2022] Open
Abstract
AbstractIt is a promising research for optimization of quantum gate in the field of quantum computation. We investigate the feasibility of implementing the single-qubit gate (Hadamard) in molecular rotational system. By applying the Multi-constraint quantum optimal control method, the excepted final states can be achieved based on the molecular rotational states both in resonant and non-resonant cases with the control pulses. The permanent electric dipole moment is ignored in non-resonance. Besides, the zero-pulse area constraint and the constant fluence constraint are employed to optimize shapes of control pulses. Finally, we show that the Hadamard gate can be realized with the high fidelity (0.9999) and also examine the dependence of the fidelity on pulse fluence as well as the control pulse.
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11
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Zhang X, Beloy K, Hassan YS, McGrew WF, Chen CC, Siegel JL, Grogan T, Ludlow AD. Subrecoil Clock-Transition Laser Cooling Enabling Shallow Optical Lattice Clocks. PHYSICAL REVIEW LETTERS 2022; 129:113202. [PMID: 36154423 DOI: 10.1103/physrevlett.129.113202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/19/2022] [Indexed: 06/16/2023]
Abstract
Laser cooling is a key ingredient for quantum control of atomic systems in a variety of settings. In divalent atoms, two-stage Doppler cooling is typically used to bring atoms to the μK regime. Here, we implement a pulsed radial cooling scheme using the ultranarrow ^{1}S_{0}-^{3}P_{0} clock transition in ytterbium to realize subrecoil temperatures, down to tens of nK. Together with sideband cooling along the one-dimensional lattice axis, we efficiently prepare atoms in shallow lattices at an energy of 6 lattice recoils. Under these conditions key limits on lattice clock accuracy and instability are reduced, opening the door to dramatic improvements. Furthermore, tunneling shifts in the shallow lattice do not compromise clock accuracy at the 10^{-19} level.
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Affiliation(s)
- X Zhang
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - K Beloy
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - Y S Hassan
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - W F McGrew
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - C-C Chen
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - J L Siegel
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - T Grogan
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
| | - A D Ludlow
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
- University of Colorado, Department of Physics, Boulder, Colorado 80309, USA
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12
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Lin J, He J, Jin M, Chen G, Wang D. Seconds-Scale Coherence on Nuclear Spin Transitions of Ultracold Polar Molecules in 3D Optical Lattices. PHYSICAL REVIEW LETTERS 2022; 128:223201. [PMID: 35714238 DOI: 10.1103/physrevlett.128.223201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Ultracold polar molecules (UPMs) are emerging as a novel and powerful platform for fundamental applications in quantum science. Here, we report characterization of the coherence between nuclear spin levels of ultracold ground-state sodium-rubidium molecules loaded into a 3D optical lattice with a nearly photon scattering limited trapping lifetime of 9(1) seconds. After identifying and compensating the main sources of decoherence, we achieve a maximum nuclear spin coherence time of T_{2}^{*}=3.3(6) s with two-photon Ramsey spectroscopy. Furthermore, based on the understanding of the main factor limiting the coherence of the two-photon Rabi transition, we obtain a Rabi line shape with linewidth below 0.8 Hz. The simultaneous realization of long lifetime and coherence time, and ultrahigh spectroscopic resolution in our system unveils the great potentials of Ultracold polar molecules in quantum simulation, computation, and metrology.
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Affiliation(s)
- Junyu Lin
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Junyu He
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Mucan Jin
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Guanghua Chen
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Dajun Wang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
- The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
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13
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Assembly and coherent control of a register of nuclear spin qubits. Nat Commun 2022; 13:2779. [PMID: 35589685 PMCID: PMC9120523 DOI: 10.1038/s41467-022-29977-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/08/2022] [Indexed: 12/01/2022] Open
Abstract
The generation of a register of highly coherent, but independent, qubits is a prerequisite to performing universal quantum computation. Here we introduce a qubit encoded in two nuclear spin states of a single 87Sr atom and demonstrate coherence approaching the minute-scale within an assembled register of individually-controlled qubits. While other systems have shown impressive coherence times through some combination of shielding, careful trapping, global operations, and dynamical decoupling, we achieve comparable coherence times while individually driving multiple qubits in parallel. We highlight that even with simultaneous manipulation of multiple qubits within the register, we observe coherence in excess of 105 times the current length of the operations, with \documentclass[12pt]{minimal}
\usepackage{amsmath}
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\usepackage{amssymb}
\usepackage{amsbsy}
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\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${T}_{2}^{{{{{\mathrm{echo}}}}}}=\left(40\pm 7\right)$$\end{document}T2echo=40±7 seconds. We anticipate that nuclear spin qubits will combine readily with the technical advances that have led to larger arrays of individually trapped neutral atoms and high-fidelity entangling operations, thus accelerating the realization of intermediate-scale quantum information processors. In large qubit registers, long coherence times and individual qubit control are difficult to achieve at the same time. Here, the authors assemble a 2D register of qubits in an array of fermionic alkaline-earth atoms, where tailored pulses can be applied to subsets of individual qubits in parallel.
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14
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Prehn A, Ibrügger M, Rempe G, Zeppenfeld M. High-Resolution "Magic"-Field Spectroscopy on Trapped Polyatomic Molecules. PHYSICAL REVIEW LETTERS 2021; 127:173602. [PMID: 34739278 DOI: 10.1103/physrevlett.127.173602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Rapid progress in cooling and trapping of molecules has enabled first experiments on high-resolution spectroscopy of trapped diatomic molecules, promising unprecedented precision. Extending this work to polyatomic molecules provides unique opportunities due to more complex geometries and additional internal degrees of freedom. Here, this is achieved by combining a homogeneous-field microstructured electric trap, rotational transitions with minimal Stark broadening at a"magic" offset electric field, and optoelectrical Sisyphus cooling of molecules to the low millikelvin temperature regime. We thereby reduce Stark broadening on the J=5←4 (K=3) transition of formaldehyde at 364 GHz to well below 1 kHz, observe Doppler-limited linewidths down to 3.8 kHz, and determine the magic-field line position with an uncertainty below 100 Hz. Our approach opens a multitude of possibilities for investigating diverse polyatomic molecule species.
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Affiliation(s)
- Alexander Prehn
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Ibrügger
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Martin Zeppenfeld
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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15
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Burchesky S, Anderegg L, Bao Y, Yu SS, Chae E, Ketterle W, Ni KK, Doyle JM. Rotational Coherence Times of Polar Molecules in Optical Tweezers. PHYSICAL REVIEW LETTERS 2021; 127:123202. [PMID: 34597100 DOI: 10.1103/physrevlett.127.123202] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Qubit coherence times are critical to the performance of any robust quantum computing platform. For quantum information processing using arrays of polar molecules, a key performance parameter is the molecular rotational coherence time. We report a 93(7) ms coherence time for rotational state qubits of laser cooled CaF molecules in optical tweezer traps, over an order of magnitude longer than previous systems. Inhomogeneous broadening due to the differential polarizability between the qubit states is suppressed by tuning the tweezer polarization and applied magnetic field to a "magic" angle. The coherence time is limited by the residual differential polarizability, implying improvement with further cooling. A single spin-echo pulse is able to extend the coherence time to nearly half a second. The measured coherence times demonstrate the potential of polar molecules as high fidelity qubits.
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Affiliation(s)
- Sean Burchesky
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Loïc Anderegg
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Yicheng Bao
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Scarlett S Yu
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Eunmi Chae
- Department of Physics, Korea University, Seongbuk-gu, Seoul 02841, South Korea
| | - Wolfgang Ketterle
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Kang-Kuen Ni
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
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16
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Anderegg L, Burchesky S, Bao Y, Yu SS, Karman T, Chae E, Ni KK, Ketterle W, Doyle JM. Observation of microwave shielding of ultracold molecules. Science 2021; 373:779-782. [PMID: 34385393 DOI: 10.1126/science.abg9502] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/07/2021] [Indexed: 11/03/2022]
Abstract
Harnessing the potential wide-ranging quantum science applications of molecules will require control of their interactions. Here, we used microwave radiation to directly engineer and tune the interaction potentials between ultracold calcium monofluoride (CaF) molecules. By merging two optical tweezers, each containing a single molecule, we probed collisions in three dimensions. The correct combination of microwave frequency and power created an effective repulsive shield, which suppressed the inelastic loss rate by a factor of six, in agreement with theoretical calculations. The demonstrated microwave shielding shows a general route to the creation of long-lived, dense samples of ultracold polar molecules and evaporative cooling.
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Affiliation(s)
- Loïc Anderegg
- Department of Physics, Harvard University, Cambridge, MA, USA. .,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Sean Burchesky
- Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Yicheng Bao
- Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Scarlett S Yu
- Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Tijs Karman
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA.,Radboud University, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ Nijmegen, Netherlands
| | - Eunmi Chae
- Department of Physics, Korea University, Seongbuk-gu, Seoul, Republic of Korea
| | - Kang-Kuen Ni
- Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Wolfgang Ketterle
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA.,Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
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17
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Gong T, Ji Z, Du J, Zhao Y, Xiao L, Jia S. Microwave-assisted coherent control of ultracold polar molecules in a ladder-type configuration of rotational states. Phys Chem Chem Phys 2021; 23:4271-4276. [PMID: 33587738 DOI: 10.1039/d1cp00202c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We demonstrate microwave-assisted coherent control of ultracold 85Rb133Cs molecules in a ladder-type configuration of rotational states. Specifically, we use a probe and a control MW field to address the transitions between the J = 1 → 2 and J = 2 → 3 rotational states of the X1Σ+(v = 0) vibrational level, respectively, and use the control field to modify the response of the probe MW transition by coherently reducing the population of the intermediate J = 2 state. We observe that an increased Rabi frequency of the control field leads to broadening of the probe spectrum splitting and a shift of the central frequency. We apply Akaike's information criterion (AIC) to conclude that the observed coherent spectral response appears across the crossover regime between electromagnetically induced transparency and Aulter-Townes splitting. Our work is a significant development in microwave-assisted quantum control of ultracold polar molecules with multilevel configuration.
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Affiliation(s)
- Ting Gong
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
| | - Zhonghua Ji
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
| | - Jiaqi Du
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
| | - Yanting Zhao
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
| | - Liantuan Xiao
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
| | - Suotang Jia
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd 92, 030006 Taiyuan, China. and Shanxi University, Collaborative Innovation Center of Extreme Optics, Wucheng Rd 92, 030006 Taiyuan, China
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18
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Hu MG, Liu Y, Nichols MA, Zhu L, Quéméner G, Dulieu O, Ni KK. Nuclear spin conservation enables state-to-state control of ultracold molecular reactions. Nat Chem 2021; 13:435-440. [PMID: 33380743 DOI: 10.1038/s41557-020-00610-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/18/2020] [Indexed: 12/13/2022]
Abstract
Quantum-state control of reactive systems has enabled microscopic probes of underlying interaction potentials and the alteration of reaction rates using quantum statistics. However, extending such control to the quantum states of reaction outcomes remains challenging. Here, we realize this goal by utilizing the conservation of nuclear spins throughout the reaction. Using resonance-enhanced multiphoton ionization spectroscopy to investigate the products formed in bimolecular reactions between ultracold KRb molecules we find that the system retains a near-perfect memory of the reactants' nuclear spins, manifested as a strong parity preference for the rotational states of the products. We leverage this effect to alter the occupation of these product states by changing the coherent superposition of initial nuclear spin states with an external magnetic field. In this way, we are able to control both the inputs and outputs of a reaction with quantum-state resolution. The techniques demonstrated here open up the possibilities to study quantum entanglement between reaction products and ultracold reaction dynamics at the state-to-state level.
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Affiliation(s)
- Ming-Guang Hu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA. .,Department of Physics, Harvard University, Cambridge, MA, USA. .,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA.
| | - Yu Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Matthew A Nichols
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Lingbang Zhu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA.,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Goulven Quéméner
- Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, Orsay, France
| | - Olivier Dulieu
- Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, Orsay, France
| | - Kang-Kuen Ni
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA. .,Department of Physics, Harvard University, Cambridge, MA, USA. .,Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA.
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19
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Dawid A, Tomza M. Magnetic properties and quench dynamics of two interacting ultracold molecules in a trap. Phys Chem Chem Phys 2020; 22:28140-28153. [PMID: 33290463 DOI: 10.1039/d0cp05542e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We theoretically investigate the magnetic properties and nonequilibrium dynamics of two interacting ultracold polar and paramagnetic molecules in a one-dimensional harmonic trap in external electric and magnetic fields. The molecules interact via a multichannel two-body contact potential, incorporating the short-range anisotropy of intermolecular interactions. We show that various magnetization states arise from the interplay of the molecular interactions, electronic spins, dipole moments, rotational structures, external fields, and spin-rotation coupling. The rich magnetization diagrams depend primarily on the anisotropy of the intermolecular interaction and the spin-rotation coupling. These specific molecular properties are challenging to calculate or measure. Therefore, we propose the quench dynamics experiments for extracting them from observing the time evolution of the analyzed system. Our results indicate the possibility of controlling the molecular few-body magnetization with the external electric field and pave the way towards studying the magnetization of ultracold molecules trapped in optical tweezers or optical lattices and their application in quantum simulation of molecular multichannel many-body Hamiltonians and quantum information storing.
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Affiliation(s)
- Anna Dawid
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
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20
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Blackmore JA, Gregory PD, Bromley SL, Cornish SL. Coherent manipulation of the internal state of ultracold 87Rb 133Cs molecules with multiple microwave fields. Phys Chem Chem Phys 2020; 22:27529-27538. [PMID: 33079114 DOI: 10.1039/d0cp04651e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We explore coherent multi-photon processes in 87Rb133Cs molecules using 3-level lambda and ladder configurations of rotational and hyperfine states, and discuss their relevance to future applications in quantum computation and quantum simulation. In the lambda configuration, we demonstrate the driving of population between two hyperfine levels of the rotational ground state via a two-photon Raman transition. Such pairs of states may be used in the future as a quantum memory, and we measure a Ramsey coherence time for a superposition of these states of 58(9) ms. In the ladder configuration, we show that we can generate and coherently populate microwave dressed states via the observation of an Autler-Townes doublet. We demonstrate that we can control the strength of this dressing by varying the intensity of the microwave coupling field. Finally, we perform spectroscopy of the rotational states of 87Rb133Cs up to N = 6, highlighting the potential of ultracold molecules for quantum simulation in synthetic dimensions. By fitting the measured transition frequencies we determine a new value of the centrifugal distortion coefficient Dv = h × 207.3(2) Hz.
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Affiliation(s)
- Jacob A Blackmore
- Joint Quantum Centre (JQC) Durham-Newcastle, Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK.
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21
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Caldwell L, Tarbutt MR. Enhancing Dipolar Interactions between Molecules Using State-Dependent Optical Tweezer Traps. PHYSICAL REVIEW LETTERS 2020; 125:243201. [PMID: 33412074 DOI: 10.1103/physrevlett.125.243201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
We show how state-dependent optical potentials can be used to trap a pair of molecules in different internal states at a separation much smaller than the wavelength of the trapping light. This close spacing greatly enhances the dipole-dipole interaction and we show how it can be used to implement two-qubit gates between molecules that are 100 times faster than existing protocols and than rotational coherence times already demonstrated. We analyze complications due to hyperfine structure, tensor light shifts, photon scattering, and collisional loss, and conclude that none is a barrier to implementing the scheme.
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Affiliation(s)
- L Caldwell
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - M R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
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22
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He X, Wang K, Zhuang J, Xu P, Gao X, Guo R, Sheng C, Liu M, Wang J, Li J, Shlyapnikov GV, Zhan M. Coherently forming a single molecule in an optical trap. Science 2020; 370:331-335. [PMID: 32972992 DOI: 10.1126/science.aba7468] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 08/27/2020] [Indexed: 11/02/2022]
Abstract
Ultracold single molecules have wide-ranging potential applications, such as ultracold chemistry, precision measurements, quantum simulation, and quantum computation. However, given the difficulty of achieving full control of a complex atom-molecule system, the coherent formation of single molecules remains a challenge. Here, we report an alternative route to coherently bind two atoms into a weakly bound molecule at megahertz levels by coupling atomic spins to their two-body relative motion in a strongly focused laser with inherent polarization gradients. The coherent nature is demonstrated by long-lived atom-molecule Rabi oscillations. We further manipulate the motional levels of the molecules and measure the binding energy precisely. This work opens the door to full control of all degrees of freedom in atom-molecule systems.
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Affiliation(s)
- Xiaodong He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China. .,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Kunpeng Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhuang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xiang Gao
- Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria.,Beijing Computational Science Research Center, Beijing 100193, China
| | - Ruijun Guo
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cheng Sheng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Min Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jin Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China.,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jiaming Li
- Department of Physics and Center for Atomic and Molecular Nanosciences, Tsinghua University, Beijing 100084, China.,Key Laboratory for Laser Plasmas (Ministry of Education), and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
| | - G V Shlyapnikov
- LPTMS, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France.,Russian Quantum Center, Skolkovo, Moscow 121025, Russia.,Van der Waals-Zeeman Institute, Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, Netherlands
| | - Mingsheng Zhan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, APM, Chinese Academy of Sciences, Wuhan 430071, China. .,Center for Cold Atom Physics, Chinese Academy of Sciences, Wuhan 430071, China
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23
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Wang Y, Wang K, Fenton EF, Lin YW, Ni KK, Hood JD. Reduction of laser intensity noise over 1 MHz band for single atom trapping. OPTICS EXPRESS 2020; 28:31209-31215. [PMID: 33115099 DOI: 10.1364/oe.405002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
We reduce the intensity noise of laser light by using an electro-optic modulator and acousto-optic modulator in series. The electro-optic modulator reduces noise at high frequency (10 kHz to 1 MHz), while the acousto-optic modulator sets the average power of the light and reduces noise at low frequency (up to 10 kHz). The light is then used to trap single sodium atoms in an optical tweezer, where the lifetime of the atoms is limited by parametric heating due to laser noise at twice the trapping frequency. With our noise eater, the noise is reduced by up to 15 dB at these frequencies and the lifetime of the atom in the optical tweezer is increased by an order of magnitude to around 6 seconds. Our technique is general and acts directly on the laser beam, expanding laser options for sensitive optical trapping applications.
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24
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Verma M, Jayich AM, Vutha AC. Electron Electric Dipole Moment Searches Using Clock Transitions in Ultracold Molecules. PHYSICAL REVIEW LETTERS 2020; 125:153201. [PMID: 33095600 DOI: 10.1103/physrevlett.125.153201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 03/06/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Permanent electric dipole moments (EDMs) of fundamental particles such as the electron are signatures of parity and time-reversal violation occurring in physics beyond the standard model. EDM measurements probe new physics at energy scales well beyond the reach of present-day colliders. Recent advances in assembling molecules from ultracold atoms have opened up new opportunities for improving the reach of EDM experiments. However, the magnetic field sensitivity of such ultracold molecules means that new measurement techniques are needed before these opportunities can be fully exploited. We present a technique that takes advantage of magnetically insensitive hyperfine clock transitions in polar molecules, offering a way to improve both the precision and accuracy of EDM searches with ultracold assembled molecules.
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Affiliation(s)
- Mohit Verma
- Department of Physics, University of Toronto, Toronto M5S 1A7, Canada
| | - Andrew M Jayich
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Amar C Vutha
- Department of Physics, University of Toronto, Toronto M5S 1A7, Canada
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25
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Yan ZZ, Park JW, Ni Y, Loh H, Will S, Karman T, Zwierlein M. Resonant Dipolar Collisions of Ultracold Molecules Induced by Microwave Dressing. PHYSICAL REVIEW LETTERS 2020; 125:063401. [PMID: 32845680 DOI: 10.1103/physrevlett.125.063401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/01/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate microwave dressing on ultracold, fermionic ^{23}Na^{40}K ground-state molecules and observe resonant dipolar collisions with cross sections exceeding 3 times the s-wave unitarity limit. The origin of these interactions is the resonant alignment of the approaching molecules' dipoles along the intermolecular axis, which leads to strong attraction. We explain our observations with a conceptually simple two-state picture based on the Condon approximation. Furthermore, we perform coupled-channel calculations that agree well with the experimentally observed collision rates. The resonant microwave-induced collisions found here enable controlled, strong interactions between molecules, of immediate use for experiments in optical lattices.
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Affiliation(s)
- Zoe Z Yan
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jee Woo Park
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Yiqi Ni
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Huanqian Loh
- Department of Physics and Centre for Quantum Technologies, National University of Singapore, 117543 Singapore
| | - Sebastian Will
- Department of Physics, Columbia University, New York 10027, USA
| | - Tijs Karman
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
| | - Martin Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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26
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Cheuk LW, Anderegg L, Bao Y, Burchesky S, Yu SS, Ketterle W, Ni KK, Doyle JM. Observation of Collisions between Two Ultracold Ground-State CaF Molecules. PHYSICAL REVIEW LETTERS 2020; 125:043401. [PMID: 32794819 DOI: 10.1103/physrevlett.125.043401] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/07/2020] [Accepted: 06/29/2020] [Indexed: 06/11/2023]
Abstract
We measure inelastic collisions between ultracold CaF molecules by combining two optical tweezers, each containing a single molecule. We observe collisions between ^{2}Σ CaF molecules in the absolute ground state |X,v=0,N=0,F=0⟩, and in excited hyperfine and rotational states. In the absolute ground state, we find a two-body loss rate of 7(4)×10^{-11} cm^{3}/s, which is below, but close to, the predicted universal loss rate.
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Affiliation(s)
- Lawrence W Cheuk
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Loïc Anderegg
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Yicheng Bao
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Sean Burchesky
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Scarlett S Yu
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Wolfgang Ketterle
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Kang-Kuen Ni
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
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27
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Zhang JT, Yu Y, Cairncross WB, Wang K, Picard LRB, Hood JD, Lin YW, Hutson JM, Ni KK. Forming a Single Molecule by Magnetoassociation in an Optical Tweezer. PHYSICAL REVIEW LETTERS 2020; 124:253401. [PMID: 32639768 DOI: 10.1103/physrevlett.124.253401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate the formation of a single NaCs molecule in an optical tweezer by magnetoassociation through an s-wave Feshbach resonance at 864.11(5) G. Starting from single atoms cooled to their motional ground states, we achieve conversion efficiencies of 47(1)%, and measure a molecular lifetime of 4.7(7) ms. By construction, the single molecules are predominantly [77(5)%] in the center-of-mass motional ground state of the tweezer. Furthermore, we produce a single p-wave molecule near 807 G by first preparing one of the atoms with one quantum of motional excitation. Our creation of a single weakly bound molecule in a designated internal state in the motional ground state of an optical tweezer is a crucial step towards coherent control of single molecules in optical tweezer arrays.
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Affiliation(s)
- Jessie T Zhang
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Yichao Yu
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - William B Cairncross
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Kenneth Wang
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Lewis R B Picard
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Jonathan D Hood
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Yen-Wei Lin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
| | - Jeremy M Hutson
- Joint Quantum Centre Durham-Newcastle, Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Kang-Kuen Ni
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138, USA
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28
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Ji Z, Gong T, He Y, Hutson JM, Zhao Y, Xiao L, Jia S. Microwave coherent control of ultracold ground-state molecules formed by short-range photoassociation. Phys Chem Chem Phys 2020; 22:13002-13007. [PMID: 32478355 DOI: 10.1039/d0cp01191f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the observation of microwave coherent control of rotational states of ultracold 85Rb133Cs molecules formed in their vibronic ground state by short-range photoassociation. Molecules are formed in the single rotational state X(v = 0, J = 1) by exciting pairs of atoms to the short-range state (2)3Π0-(v = 11, J = 0), followed by spontaneous decay. We use depletion spectroscopy to record the dynamic evolution of the population distribution and observe clear Rabi oscillations while irradiating on a microwave transition between coupled neighbouring rotational levels. A density-matrix formalism that accounts for longitudinal and transverse decay times reproduces both the dynamic evolution during the coherent process and the equilibrium population. The coherent control reported here is valuable both for investigating coherent quantum effects and for applications of cold polar molecules produced by continuous short-range photoassociation.
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Affiliation(s)
- Zhonghua Ji
- Shanxi University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Wucheng Rd. 92, 030006 Taiyuan, China.
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29
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Caldwell L, Williams HJ, Fitch NJ, Aldegunde J, Hutson JM, Sauer BE, Tarbutt MR. Long Rotational Coherence Times of Molecules in a Magnetic Trap. PHYSICAL REVIEW LETTERS 2020; 124:063001. [PMID: 32109098 DOI: 10.1103/physrevlett.124.063001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
Polar molecules in superpositions of rotational states exhibit long-range dipolar interactions, but maintaining their coherence in a trapped sample is a challenge. We present calculations that show many laser-coolable molecules have convenient rotational transitions that are exceptionally insensitive to magnetic fields. We verify this experimentally for CaF where we find a transition with sensitivity below 5 Hz G^{-1} and use it to demonstrate a rotational coherence time of 6.4(8) ms in a magnetic trap. Simulations suggest it is feasible to extend this to more than 1 s using a smaller cloud in a biased magnetic trap.
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Affiliation(s)
- L Caldwell
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - H J Williams
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - N J Fitch
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - J Aldegunde
- Departamento de Quimica Fisica, Universidad de Salamanca, E-37008 Salamanca, Spain
| | - Jeremy M Hutson
- Joint Quantum Centre (JQC) Durham-Newcastle, Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - B E Sauer
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - M R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
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30
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Zhou Y, Shagam Y, Cairncross WB, Ng KB, Roussy TS, Grogan T, Boyce K, Vigil A, Pettine M, Zelevinsky T, Ye J, Cornell EA. Second-Scale Coherence Measured at the Quantum Projection Noise Limit with Hundreds of Molecular Ions. PHYSICAL REVIEW LETTERS 2020; 124:053201. [PMID: 32083904 DOI: 10.1103/physrevlett.124.053201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Cold molecules provide an excellent platform for quantum information, cold chemistry, and precision measurement. Certain molecules have enhanced sensitivity to beyond standard model physics, such as the electron's electric dipole moment (eEDM). Molecular ions are easily trappable and are therefore particularly attractive for precision measurements where sensitivity scales with interrogation time. Here, we demonstrate a spin precession measurement with second-scale coherence at the quantum projection noise (QPN) limit with hundreds of trapped molecular ions, chosen for their sensitivity to the eEDM rather than their amenability to state control and readout. Orientation-resolved resonant photodissociation allows us to simultaneously measure two quantum states with opposite eEDM sensitivity, reaching the QPN limit and fully exploiting the high count rate and long coherence.
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Affiliation(s)
- Yan Zhou
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Yuval Shagam
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - William B Cairncross
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Kia Boon Ng
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Tanya S Roussy
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Tanner Grogan
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Kevin Boyce
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Antonio Vigil
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Madeline Pettine
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Tanya Zelevinsky
- Department of Physics, Columbia University, New York, New York 10027-5255, USA
| | - Jun Ye
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Eric A Cornell
- JILA, NIST, and University of Colorado and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA
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31
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Christianen A, Zwierlein MW, Groenenboom GC, Karman T. Photoinduced Two-Body Loss of Ultracold Molecules. PHYSICAL REVIEW LETTERS 2019; 123:123402. [PMID: 31633957 DOI: 10.1103/physrevlett.123.123402] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Indexed: 06/10/2023]
Abstract
The lifetime of nonreactive ultracold bialkali gases was conjectured to be limited by sticky collisions amplifying three-body loss. We show that the sticking times were previously overestimated and do not support this hypothesis. We find that electronic excitation of NaK+NaK collision complexes by the trapping laser leads to the experimentally observed two-body loss. We calculate the excitation rate with a quasiclassical, statistical model employing ab initio potentials and transition dipole moments. Using longer laser wavelengths or repulsive box potentials may suppress the losses.
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Affiliation(s)
- Arthur Christianen
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Martin W Zwierlein
- MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Gerrit C Groenenboom
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Tijs Karman
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
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32
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Liu L, Zhang DC, Yang H, Liu YX, Nan J, Rui J, Zhao B, Pan JW. Observation of Interference between Resonant and Detuned stirap in the Adiabatic Creation of ^{23}Na^{40}K Molecules. PHYSICAL REVIEW LETTERS 2019; 122:253201. [PMID: 31347860 DOI: 10.1103/physrevlett.122.253201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Indexed: 06/10/2023]
Abstract
Stimulated Raman adiabatic passage (stirap) allows efficiently transferring the populations between two discrete quantum states and has been used to prepare molecules in their rovibrational ground state. In realistic molecules, a well-resolved intermediate state is usually selected to implement the resonant stirap. Because of the complex molecular level structures, the detuned stirap always coexists with the resonant stirap and may cause unexpected interference phenomenon. However, it is generally accepted that the detuned stirap can be neglected if compared with the resonant stirap. Here we report on the first observation of interference between the resonant and detuned stirap in the adiabatic creation of ^{23}Na^{40}K ground-state molecules. The interference is identified by observing that the number of Feshbach molecules after a round-trip stirap oscillates as a function of the hold time, with a visibility of about 90%. This occurs even if the intermediate excited states are well resolved, and the single-photon detuning of the detuned stirap is about 1 order of magnitude larger than the linewidth of the excited state and the Rabi frequencies of the stirap lasers. Moreover, the observed interference indicates that if more than one hyperfine level of the ground state is populated, the stirap prepares a coherent superposition state among them, but not an incoherent mixed state. Further, the purity of the hyperfine levels of the created ground state can be quantitatively determined by the visibility of the oscillation.
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Affiliation(s)
- Lan Liu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - De-Chao Zhang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Huan Yang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Ya-Xiong Liu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jue Nan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jun Rui
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Bo Zhao
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
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33
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The Role of Relativistic Many-Body Theory in Electron Electric Dipole Moment Searches Using Cold Molecules. ATOMS 2019. [DOI: 10.3390/atoms7020058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this review article, we survey some of our results pertaining to the search for the electric dipole moment of the electron (eEDM), using heavy polar molecules. In particular, we focus on the relativistic coupled cluster method (RCCM) and its applications to eEDM searches in YbF, HgX (X = F, Cl, Br, and I), BaF, HgA (A = Li, Na, and K), and YbOH. Our results are presented in a systematic manner, by first introducing the eEDM and its measurement using molecules, the importance of relativistic many-body theory, and finally our results, followed by future prospects.
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34
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Gonzalo I, Antón MA. Entangling non planar molecules via inversion doublet transition with negligible spontaneous emission. Phys Chem Chem Phys 2019; 21:10523-10531. [PMID: 31070606 DOI: 10.1039/c8cp07764a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We analyze theoretically the entanglement between two non-planar and light identical molecules (e.g., pyramidal NH3) that present inversion doubling due to the internal spatial inversion of their nuclear conformations by tunneling. The peculiarity of this system lies in the simplicity of this type of molecular system in which two near levels can be connected by an allowed electric dipole transition with considerable value of the dipole moment transition and negligible spontaneous emission because the transition is in the microwave or far-infrared range. These properties give place to entanglement states oscillating by free evolution with frequency determined by the dipole-dipole interaction and negligible spontaneous decay, which allows consideration of an efficient quantum Zeno effect by frequent measurements of one of the entangled states. If the molecules are initially both in the upper (or lower) eigenstate, the system evolves under an external radiation field, which can induce oscillations of the generated entangled states, with frequency of the order of the Rabi frequency of the field. For a certain detuning, a symmetric entangled state, which is an eigenstate of the collective system, can be populated, and given its negligible spontaneous emission, could be maintained for a time limited only by external decoherence processes, which could be minimized. Although the data used are those of the NH3 molecule, other molecules could present the same advantageous features.
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Affiliation(s)
- Isabel Gonzalo
- Departamento de Óptica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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35
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Barker DS, Norrgard EB, Klimov NN, Fedchak JA, Scherschligt J, Eckel S. Single-beam Zeeman slower and magneto-optical trap using a nanofabricated grating. PHYSICAL REVIEW APPLIED 2019; 11:77. [PMID: 33299903 DOI: 10.1038/s42005-019-0181-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/07/2019] [Indexed: 05/22/2023]
Abstract
We demonstrate a compact (0.25 L) system for laser cooling and trapping atoms from a heated dispenser source. Our system uses a nanofabricated diffraction grating to generate a magnetooptical trap (MOT) using a single input laser beam. An aperture in the grating allows atoms from the dispenser to be loaded from behind the chip, increasing the interaction distance of atoms with the cooling light. To take full advantage of this increased distance, we extend the magnetic field gradient of the MOT to create a Zeeman slower. The MOT traps approximately 106 7Li atoms emitted from an effusive source with loading rates greater than 106 s-1. Our design is portable to a variety of atomic and molecular species and could be a principal component of miniaturized cold-atom-based technologies.
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Affiliation(s)
- D S Barker
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - E B Norrgard
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - N N Klimov
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J A Fedchak
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J Scherschligt
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - S Eckel
- Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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36
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Seeßelberg F, Luo XY, Li M, Bause R, Kotochigova S, Bloch I, Gohle C. Extending Rotational Coherence of Interacting Polar Molecules in a Spin-Decoupled Magic Trap. PHYSICAL REVIEW LETTERS 2018; 121:253401. [PMID: 30608826 DOI: 10.1103/physrevlett.121.253401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Indexed: 06/09/2023]
Abstract
Superpositions of rotational states in polar molecules induce strong, long-range dipolar interactions. Here we extend the rotational coherence by nearly 1 order of magnitude to 8.7(6) ms in a dilute gas of polar ^{23}Na^{40}K molecules in an optical trap. We demonstrate spin-decoupled magic trapping, which cancels first-order and reduces second-order differential light shifts. The latter is achieved with a dc electric field that decouples nuclear spin, rotation, and trapping light field. We observe density-dependent coherence times, which can be explained by dipolar interactions in the bulk gas.
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Affiliation(s)
| | - Xin-Yu Luo
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
| | - Ming Li
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Roman Bause
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
| | | | - Immanuel Bloch
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München, Germany
| | - Christoph Gohle
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
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37
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Chen L, Lau JA, Schwarzer D, Meyer J, Verma VB, Wodtke AM. The Sommerfeld ground-wave limit for a molecule adsorbed at a surface. Science 2018; 363:158-161. [DOI: 10.1126/science.aav4278] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 11/12/2018] [Indexed: 11/02/2022]
Abstract
Using a mid-infrared emission spectrometer based on a superconducting nanowire single-photon detector, we observed the dynamics of vibrational energy pooling of carbon monoxide (CO) adsorbed at the surface of a sodium chloride (NaCl) crystal. After exciting a majority of the CO molecules to their first vibrationally excited state (v = 1), we observed infrared emission from states up to v = 27. Kinetic Monte Carlo simulations showed that vibrational energy collects in a few CO molecules at the expense of those up to eight lattice sites away by selective excitation of NaCl’s transverse phonons. The vibrating CO molecules behave like classical oscillating dipoles, losing their energy to NaCl lattice vibrations via the electromagnetic near-field. This is analogous to Sommerfeld’s description of radio transmission along Earth’s surface by ground waves.
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38
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Ni KK, Rosenband T, Grimes DD. Dipolar exchange quantum logic gate with polar molecules. Chem Sci 2018; 9:6830-6838. [PMID: 30310615 PMCID: PMC6115616 DOI: 10.1039/c8sc02355g] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/12/2018] [Indexed: 11/21/2022] Open
Abstract
We propose a two-qubit gate based on dipolar exchange interactions between individually addressable ultracold polar molecules in an array of optical dipole traps. Our proposal treats the full Hamiltonian of the 1Σ+ molecule NaCs, utilizing a pair of nuclear spin states as storage qubits. A third rotationally excited state with rotation-hyperfine coupling enables switchable electric dipolar exchange interactions between two molecules to generate an iSWAP gate. All three states are insensitive to external magnetic and electric fields. Impacts on gate fidelity due to coupling to other molecular states, imperfect ground-state cooling, blackbody radiation and vacuum spontaneous emission are small, leading to potential fidelity above 99.99% in a coherent quantum system that can be scaled by purely optical means.
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Affiliation(s)
- Kang-Kuen Ni
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , USA .
- Department of Physics , Harvard University , Cambridge , Massachusetts 02138 , USA
- Harvard-MIT Center for Ultracold Atoms , Cambridge , Massachusetts 02138 , USA
| | - Till Rosenband
- Department of Physics , Harvard University , Cambridge , Massachusetts 02138 , USA
| | - David D Grimes
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , USA .
- Department of Physics , Harvard University , Cambridge , Massachusetts 02138 , USA
- Harvard-MIT Center for Ultracold Atoms , Cambridge , Massachusetts 02138 , USA
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39
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Williams HJ, Caldwell L, Fitch NJ, Truppe S, Rodewald J, Hinds EA, Sauer BE, Tarbutt MR. Magnetic Trapping and Coherent Control of Laser-Cooled Molecules. PHYSICAL REVIEW LETTERS 2018; 120:163201. [PMID: 29756945 DOI: 10.1103/physrevlett.120.163201] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate coherent microwave control of the rotational, hyperfine, and Zeeman states of ultracold CaF molecules, and the magnetic trapping of these molecules in a single, selectable quantum state. We trap about 5×10^{3} molecules for almost 2 s at a temperature of 70(8) μK and a density of 1.2×10^{5} cm^{-3}. We measure the state-specific loss rate due to collisions with background helium.
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Affiliation(s)
- H J Williams
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - L Caldwell
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - N J Fitch
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - S Truppe
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - J Rodewald
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - E A Hinds
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - B E Sauer
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - M R Tarbutt
- Centre for Cold Matter, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
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40
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Kozyryev I, Hutzler NR. Precision Measurement of Time-Reversal Symmetry Violation with Laser-Cooled Polyatomic Molecules. PHYSICAL REVIEW LETTERS 2017; 119:133002. [PMID: 29341669 DOI: 10.1103/physrevlett.119.133002] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Indexed: 06/07/2023]
Abstract
Precision searches for time-reversal symmetry violating interactions in polar molecules are extremely sensitive probes of high energy physics beyond the standard model. To extend the reach of these probes into the PeV regime, long coherence times and large count rates are necessary. Recent advances in laser cooling of polar molecules offer one important tool-optical trapping. However, the types of molecules that have been laser cooled so far do not have the highly desirable combination of features for new physics searches, such as the ability to fully polarize and the existence of internal comagnetometer states. We show that by utilizing the internal degrees of freedom present only in molecules with at least three atoms, these features can be attained simultaneously with molecules that have simple structure and are amenable to laser cooling and trapping.
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Affiliation(s)
- Ivan Kozyryev
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Nicholas R Hutzler
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
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41
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Bohn JL, Rey AM, Ye J. Cold molecules: Progress in quantum engineering of chemistry and quantum matter. Science 2017; 357:1002-1010. [PMID: 28883071 DOI: 10.1126/science.aam6299] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cooling atoms to ultralow temperatures has produced a wealth of opportunities in fundamental physics, precision metrology, and quantum science. The more recent application of sophisticated cooling techniques to molecules, which has been more challenging to implement owing to the complexity of molecular structures, has now opened the door to the longstanding goal of precisely controlling molecular internal and external degrees of freedom and the resulting interaction processes. This line of research can leverage fundamental insights into how molecules interact and evolve to enable the control of reaction chemistry and the design and realization of a range of advanced quantum materials.
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Affiliation(s)
- John L Bohn
- JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, CO 80309-0440, USA.
| | - Ana Maria Rey
- JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, CO 80309-0440, USA.
| | - Jun Ye
- JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, CO 80309-0440, USA.
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