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Biagioni G, Antolini N, Donelli B, Pezzè L, Smerzi A, Fattori M, Fioretti A, Gabbanini C, Inguscio M, Tanzi L, Modugno G. Measurement of the superfluid fraction of a supersolid by Josephson effect. Nature 2024; 629:773-777. [PMID: 38720083 PMCID: PMC11111407 DOI: 10.1038/s41586-024-07361-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 03/27/2024] [Indexed: 05/24/2024]
Abstract
A new class of superfluids and superconductors with spatially periodic modulation of the superfluid density is arising1-12. It might be related to the supersolid phase of matter, in which the spontaneous breaking of gauge and translational symmetries leads to a spatially modulated macroscopic wavefunction13-16. This relation was recognized only in some cases1,2,5-9 and there is the need for a universal property quantifying the differences between supersolids and ordinary matter, such as the superfluid fraction, which measures the reduction in superfluid stiffness resulting from the spatial modulation16-18. The superfluid fraction was introduced long ago16, but it has not yet been assessed experimentally. Here we demonstrate an innovative method to measure the superfluid fraction based on the Josephson effect, a ubiquitous phenomenon associated with the presence of a physical barrier between two superfluids or superconductors19, which might also be expected for supersolids20, owing to the spatial modulation. We demonstrate that individual cells of a supersolid can sustain Josephson oscillations and we show that, from the current-phase dynamics, we can derive directly the superfluid fraction. Our study of a cold-atom dipolar supersolid7 reveals a relatively large sub-unity superfluid fraction that makes realistic the study of previously unknown phenomena such as partially quantized vortices and supercurrents16-18. Our results open a new direction of research that may unify the description of all supersolid-like systems.
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Affiliation(s)
- G Biagioni
- Dipartimento di Fisica e Astronomia, Università degli studi di Firenze, Sesto Fiorentino, Italy
- CNR-INO, Sede di Pisa, Pisa, Italy
| | - N Antolini
- CNR-INO, Sede di Pisa, Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
| | - B Donelli
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
- CNR-INO, Sede di Firenze, Firenze, Italy
- Quantum Science and Technology in Arcetri (QSTAR), Firenze, Italy
- Università degli Studi di Napoli Federico II, Napoli, Italy
| | - L Pezzè
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
- CNR-INO, Sede di Firenze, Firenze, Italy
- Quantum Science and Technology in Arcetri (QSTAR), Firenze, Italy
| | - A Smerzi
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy.
- CNR-INO, Sede di Firenze, Firenze, Italy.
- Quantum Science and Technology in Arcetri (QSTAR), Firenze, Italy.
| | - M Fattori
- Dipartimento di Fisica e Astronomia, Università degli studi di Firenze, Sesto Fiorentino, Italy
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
- CNR-INO, Sede di Sesto Fiorentino, Sesto Fiorentino, Italy
| | | | | | - M Inguscio
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
- Dipartimento di Ingegneria, Università Campus Bio-Medico di Roma, Roma, Italy
| | - L Tanzi
- CNR-INO, Sede di Pisa, Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy
| | - G Modugno
- Dipartimento di Fisica e Astronomia, Università degli studi di Firenze, Sesto Fiorentino, Italy.
- CNR-INO, Sede di Pisa, Pisa, Italy.
- European Laboratory for Non-Linear Spectroscopy, Università degli studi di Firenze, Sesto Fiorentino, Italy.
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Poli E, Bland T, White SJM, Mark MJ, Ferlaino F, Trabucco S, Mannarelli M. Glitches in Rotating Supersolids. PHYSICAL REVIEW LETTERS 2023; 131:223401. [PMID: 38101354 DOI: 10.1103/physrevlett.131.223401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/11/2023] [Accepted: 10/20/2023] [Indexed: 12/17/2023]
Abstract
Glitches, spin-up events in neutron stars, are of prime interest, as they reveal properties of nuclear matter at subnuclear densities. We numerically investigate the glitch mechanism due to vortex unpinning using analogies between neutron stars and dipolar supersolids. We explore the vortex and crystal dynamics during a glitch and its dependence on the supersolid quality, providing a tool to study glitches from different radial depths of a neutron star. Benchmarking our theory against neutron-star observations, our work will open a new avenue for the quantum simulation of stellar objects from Earth.
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Affiliation(s)
- Elena Poli
- Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria
| | - Thomas Bland
- Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria
| | - Samuel J M White
- Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Manfred J Mark
- Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Francesca Ferlaino
- Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Silvia Trabucco
- INFN Laboratori Nazionali del Gran Sasso, 67100 Assergi (AQ), Italy
- Gran Sasso Science Institute, 67100 L'Aquila, Italy
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3
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Klaus L, Bland T, Poli E, Politi C, Lamporesi G, Casotti E, Bisset RN, Mark MJ, Ferlaino F. Observation of vortices and vortex stripes in a dipolar condensate. NATURE PHYSICS 2022; 18:1453-1458. [PMID: 36506337 PMCID: PMC9726643 DOI: 10.1038/s41567-022-01793-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/08/2022] [Indexed: 06/17/2023]
Abstract
Quantized vortices are a prototypical feature of superfluidity that have been observed in multiple quantum gas experiments. But the occurrence of vortices in dipolar quantum gases-a class of ultracold gases characterized by long-range anisotropic interactions-has not been reported yet. Here we exploit the anisotropic nature of the dipole-dipole interaction of a dysprosium Bose-Einstein condensate to induce angular symmetry breaking in an otherwise cylindrically symmetric pancake-shaped trap. Tilting the magnetic field towards the radial plane deforms the cloud into an ellipsoid, which is then set into rotation. At stirring frequencies approaching the radial trap frequency, we observe the generation of dynamically unstable surface excitations, which cause angular momentum to be pumped into the system through vortices. Under continuous rotation, the vortices arrange into a stripe configuration along the field, in close agreement with numerical simulations.
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Affiliation(s)
- Lauritz Klaus
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Thomas Bland
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Elena Poli
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Claudia Politi
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Giacomo Lamporesi
- INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, Povo, Italy
| | - Eva Casotti
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Russell N. Bisset
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Manfred J. Mark
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
| | - Francesca Ferlaino
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria
- Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
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