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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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2
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Ruttley DK, Guttridge A, Spence S, Bird RC, Le Sueur CR, Hutson JM, Cornish SL. Formation of Ultracold Molecules by Merging Optical Tweezers. PHYSICAL REVIEW LETTERS 2023; 130:223401. [PMID: 37327422 DOI: 10.1103/physrevlett.130.223401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/24/2023] [Accepted: 04/25/2023] [Indexed: 06/18/2023]
Abstract
We demonstrate the formation of a single RbCs molecule during the merging of two optical tweezers, one containing a single Rb atom and the other a single Cs atom. Both atoms are initially predominantly in the motional ground states of their respective tweezers. We confirm molecule formation and establish the state of the molecule formed by measuring its binding energy. We find that the probability of molecule formation can be controlled by tuning the confinement of the traps during the merging process, in good agreement with coupled-channel calculations. We show that the conversion efficiency from atoms to molecules using this technique is comparable to magnetoassociation.
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Affiliation(s)
- Daniel K Ruttley
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Alexander Guttridge
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Stefan Spence
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Robert C Bird
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - C Ruth Le Sueur
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Jeremy M Hutson
- Department of Chemistry and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Simon L Cornish
- Department of Physics and Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham, DH1 3LE, United Kingdom
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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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Gregory PD, Blackmore JA, Bromley SL, Cornish SL. Loss of Ultracold ^{87}Rb^{133}Cs Molecules via Optical Excitation of Long-Lived Two-Body Collision Complexes. PHYSICAL REVIEW LETTERS 2020; 124:163402. [PMID: 32383932 DOI: 10.1103/physrevlett.124.163402] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
We show that the lifetime of ultracold ground-state ^{87}Rb^{133}Cs molecules in an optical trap is limited by fast optical excitation of long-lived two-body collision complexes. We partially suppress this loss mechanism by applying square-wave modulation to the trap intensity, such that the molecules spend 75% of each modulation cycle in the dark. By varying the modulation frequency, we show that the lifetime of the collision complex is 0.53±0.06 ms in the dark. We find that the rate of optical excitation of the collision complex is 3_{-2}^{+4}×10^{3} W^{-1} cm^{2} s^{-1} for λ=1550 nm, leading to a lifetime of <100 ns for typical trap intensities. These results explain the two-body loss observed in experiments on nonreactive bialkali molecules.
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Affiliation(s)
- Philip D Gregory
- Department of Physics, Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Jacob A Blackmore
- Department of Physics, Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Sarah L Bromley
- Department of Physics, Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Simon L Cornish
- Department of Physics, Joint Quantum Centre (JQC) Durham-Newcastle, Durham University, South Road, Durham DH1 3LE, United Kingdom
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Gregory PD, Frye MD, Blackmore JA, Bridge EM, Sawant R, Hutson JM, Cornish SL. Sticky collisions of ultracold RbCs molecules. Nat Commun 2019; 10:3104. [PMID: 31308368 PMCID: PMC6629645 DOI: 10.1038/s41467-019-11033-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/13/2019] [Indexed: 12/04/2022] Open
Abstract
Understanding and controlling collisions is crucial to the burgeoning field of ultracold molecules. All experiments so far have observed fast loss of molecules from the trap. However, the dominant mechanism for collisional loss is not well understood when there are no allowed 2-body loss processes. Here we experimentally investigate collisional losses of nonreactive ultracold 87Rb133Cs molecules, and compare our findings with the sticky collision hypothesis that pairs of molecules form long-lived collision complexes. We demonstrate that loss of molecules occupying their rotational and hyperfine ground state is best described by second-order rate equations, consistent with the expectation for complex-mediated collisions, but that the rate is lower than the limit of universal loss. The loss is insensitive to magnetic field but increases for excited rotational states. We demonstrate that dipolar effects lead to significantly faster loss for an incoherent mixture of rotational states.
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Affiliation(s)
- Philip D Gregory
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Physics, Durham University, Durham, DH1 3LE, UK
| | - Matthew D Frye
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Jacob A Blackmore
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Physics, Durham University, Durham, DH1 3LE, UK
| | - Elizabeth M Bridge
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Physics, Durham University, Durham, DH1 3LE, UK
| | - Rahul Sawant
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Physics, Durham University, Durham, DH1 3LE, UK
| | - Jeremy M Hutson
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Chemistry, Durham University, Durham, DH1 3LE, UK.
| | - Simon L Cornish
- Joint Quantum Centre (JQC), Durham-Newcastle, Department of Physics, Durham University, Durham, DH1 3LE, UK.
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