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Sobirey L, Biss H, Luick N, Bohlen M, Moritz H, Lompe T. Observing the Influence of Reduced Dimensionality on Fermionic Superfluids. PHYSICAL REVIEW LETTERS 2022; 129:083601. [PMID: 36053698 DOI: 10.1103/physrevlett.129.083601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Understanding the origins of unconventional superconductivity has been a major focus of condensed matter physics for many decades. While many questions remain unanswered, experiments have found the highest critical temperatures in layered two-dimensional materials. However, to what extent the remarkable stability of these strongly correlated 2D superfluids is affected by their reduced dimensionality is still an open question. Here, we use dilute gases of ultracold fermionic atoms as a model system to directly observe the influence of dimensionality on the stability of strongly interacting fermionic superfluids. We find that the superfluid gap follows the same universal function of the interaction strength regardless of dimensionality, which suggests that there is no inherent difference in the stability of two- and three-dimensional fermionic superfluids. Finally, we compare our data to results from solid state systems and find a similar relation between the interaction strength and the gap for a wide range of two- and three-dimensional superconductors.
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Affiliation(s)
- Lennart Sobirey
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Hauke Biss
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Niclas Luick
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Markus Bohlen
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Henning Moritz
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Thomas Lompe
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
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Masuhara N, Watson BC, Meisel MW. Direct measurement of the energy gap of superfluid 3He-B in the low-temperature limit. PHYSICAL REVIEW LETTERS 2000; 85:2537-2540. [PMID: 10978101 DOI: 10.1103/physrevlett.85.2537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2000] [Indexed: 05/23/2023]
Abstract
The zero-temperature limit of the energy gap, Delta(P,T-->0), of superfluid 3He-B has been measured at T/T(c) less, similar0.25, near 0.1 and 4.8 bars, and in zero magnetic field. The energy gap was determined from the 2Delta pair-breaking edge of an acoustic signal obtained by novel, pulsed Fourier-Transform ultrasonic spectroscopy. Our results are independent of the temperature scale and the theoretical model of the gap. The values for Delta(P,T-->0) are lower than predicted by the weak-coupling-plus theory, and the Delta(P approximately 0.1 bars,T-->0) values are lower than predicted by BCS theory. The data indicate that Delta(P,T-->0) of superfluid 3He-B is not well modeled at the lowest pressures.
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Affiliation(s)
- N Masuhara
- Department of Physics and The Center for Ultralow Temperature Research, Microkelvin Research Laboratory, University of Florida, P. O. Box 118440, Gainesville, Florida 32611-8440, USA
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Cousins DJ, Enrico MP, Fisher SN, Phillipson SL, Pickett GR, Shaw NS, Thibault PJ. Probing the A-B Phase Interface in Superfluid 3He by Andreev Reflection of a Quasiparticle Beam. PHYSICAL REVIEW LETTERS 1996; 77:5245-5248. [PMID: 10062752 DOI: 10.1103/physrevlett.77.5245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Schiffer P, O'Keefe MT, Fukuyama H, Osheroff DD. Low-temperature studies of the NMR frequency shift in superfluid 3He-A. PHYSICAL REVIEW LETTERS 1992; 69:3096-3099. [PMID: 10046724 DOI: 10.1103/physrevlett.69.3096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Movshovich R, Varoquaux E, Kim N, Lee DM. Fivefold splitting of the squashing collective mode of superfluid 3He-B by a magnetic field. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:332-340. [PMID: 9998250 DOI: 10.1103/physrevb.44.332] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Order-Parameter Collective Modes in Superfluid 3He. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/b978-0-444-87476-4.50013-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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