Helium II will "creep" along surfaces in order to find its own level—after a short while, the levels in the two containers will equalize. The Rollin film also covers the interior of the larger container; if it were not sealed, the helium II would creep out and escape.The liquid helium is in the superfluid phase. A thin invisible film creeps up the inside wall of the bowl and down on the outside. A drop forms. It will fall off into the liquid helium below. This will repeat until the cup is empty—provided the liquid remains superfluid.
Superfluidity often co-occurs with Bose–Einstein condensation, but neither phenomenon is directly related to the other; not all Bose–Einstein condensates can be regarded as superfluids, and not all superfluids are Bose–Einstein condensates.[citation needed]
Superfluidity was discovered in helium-4 by Pyotr Kapitsa[2] and independently by John F. Allen and Don Misener[3] in 1937. Onnes possibly observed the superfluid phase transition on August 2 1911, the same day that he observed superconductivity in mercury.[4] It has since been described through phenomenology and microscopic theories.
In liquid helium-4, the superfluidity occurs at far higher temperatures than it does in helium-3. Each atom of helium-4 is a boson particle, by virtue of its integer spin. A helium-3 atom is a fermion particle; it can form bosons only by pairing with another particle like itself at much lower temperatures. The discovery of superfluidity in helium-3 was the basis for the award of the 1996 Nobel Prize in Physics.[1] This process is similar to the electron pairing in superconductivity.
Ultracold atomic gasesEdit
Superfluidity in an ultracold fermionic gas was experimentally proven by Wolfgang Ketterle and his team who observed quantum vortices in lithium-6 at a temperature of 50 nK at MIT in April 2005.[5][6] Such vortices had previously been observed in an ultracold bosonic gas using rubidium-87 in 2000,[7] and more recently in two-dimensional gases.[8] As early as 1999, Lene Hau created such a condensate using sodium atoms[9] for the purpose of slowing light, and later stopping it completely.[10] Her team subsequently used this system of compressed light[11] to generate the superfluid analogue of shock waves and tornadoes:[12]
These dramatic excitations result in the formation of solitons that in turn decay into quantized vortices—created far out of equilibrium, in pairs of opposite circulation—revealing directly the process of superfluid breakdown in Bose–Einstein condensates. With a double light-roadblock setup, we can generate controlled collisions between shock waves resulting in completely unexpected, nonlinear excitations. We have observed hybrid structures consisting of vortex rings embedded in dark solitonic shells. The vortex rings act as 'phantom propellers' leading to very rich excitation dynamics.
— Lene Hau, SIAM Conference on Nonlinear Waves and Coherent Structures
Superfluids in astrophysicsEdit
The idea that superfluidity exists inside neutron stars was first proposed by Arkady Migdal.[13][14] By analogy with electrons inside superconductors forming Cooper pairs because of electron-lattice interaction, it is expected that nucleons in a neutron star at sufficiently high density and low temperature can also form Cooper pairs because of the long-range attractive nuclear force and lead to superfluidity and superconductivity.[15]
The ultimate goal of the approach is to develop scientific models that unify quantum mechanics (describing three of the four known fundamental interactions) with gravity. This makes SVT a candidate for the theory of quantum gravity and an extension of the Standard Model.
It is hoped that development of such theory would unify into a single consistent model of all fundamental interactions, and to describe all known interactions and elementary particles as different manifestations of the same entity, superfluid vacuum.
On the macro-scale a larger similar phenomenon has been suggested as happening in the murmurations of starlings. The rapidity of change in flight patterns mimics the phase change leading to superfluidity in some liquid states.[16]
Light behaves like a superfluid in various applications such as Poisson's Spot. As the liquid helium shown above, light will travel along the surface of an obstacle before continuing along its trajectory. Since light is not affected by local gravity its "level" becomes its own trajectory and velocity. Another example is how a beam of light travels through the hole of an aperture and along its backside before diffraction.
^ ab"The Nobel Prize in Physics 1996 – Advanced Information". www.nobelprize.org. Retrieved 2017-02-10.
^Kapitza, P. (1938). "Viscosity of Liquid Helium Below the λ-Point". Nature. 141 (3558): 74. Bibcode:1938Natur.141...74K. doi:10.1038/141074a0. S2CID 3997900.
^Allen, J. F.; Misener, A. D. (1938). "Flow of Liquid Helium II". Nature. 142 (3597): 643. Bibcode:1938Natur.142..643A. doi:10.1038/142643a0. S2CID 4135906.
^van Delft, Dirk; Kes, Peter (2010-09-01). "The discovery of superconductivity". Physics Today. 63 (9): 38–43. doi:10.1063/1.3490499. ISSN 0031-9228.
^"MIT physicists create new form of matter". mit.edu. 22 June 2005. Retrieved November 22, 2010.
^Grimm, R. (2005). "Low-temperature physics: A quantum revolution". Nature. 435 (7045): 1035–1036. Bibcode:2005Natur.435.1035G. doi:10.1038/4351035a. PMID 15973388. S2CID 7262637.
^Madison, K.; Chevy, F.; Wohlleben, W.; Dalibard, J. (2000). "Vortex Formation in a Stirred Bose–Einstein Condensate". Physical Review Letters. 84 (5): 806–809. arXiv:cond-mat/9912015. Bibcode:2000PhRvL..84..806M. doi:10.1103/PhysRevLett.84.806. PMID 11017378. S2CID 9128694.
^Burnett, K. (2007). "Atomic physics: Cold gases venture into Flatland". Nature Physics. 3 (9): 589. Bibcode:2007NatPh...3..589B. doi:10.1038/nphys704.
^Hau, L. V.; Harris, S. E.; Dutton, Z.; Behroozi, C. H. (1999). "Light speed reduction to 17 metres per second in an ultracold atomic gas". Nature. 397 (6720): 594–598. Bibcode:1999Natur.397..594V. doi:10.1038/17561. S2CID 4423307.
^Hau, Lene (September 9–12, 2006). "Shocking Bose–Einstein Condensates with Slow Light". SIAM.org. Society for Industrial and Applied Mathematics.
^A. B. Migdal (1959). "Superfluidity and the moments of inertia of nuclei". Nucl. Phys. 13 (5): 655–674. Bibcode:1959NucPh..13..655M. doi:10.1016/0029-5582(59)90264-0.
^A. B. Migdal (1960). "Superfluidity and the Moments of Inertia of Nuclei". Soviet Phys. JETP. 10 (5): 176. Bibcode:1959NucPh..13..655M. doi:10.1016/0029-5582(59)90264-0.
^U. Lombardo & H.-J. Schulze (2001). "Superfluidity in Neutron Star Matter". Physics of Neutron Star Interiors. Lecture Notes in Physics. Vol. 578. pp. 30–53. arXiv:astro-ph/0012209. doi:10.1007/3-540-44578-1_2. ISBN978-3-540-42340-9. S2CID 586149.
^Attanasi, A.; Cavagna, A.; Del Castello, L.; Giardina, I.; Grigera, T. S.; Jelić, A.; Melillo, S.; Parisi, L.; Pohl, O.; Shen, E.; Viale, M. (2014). "Information transfer and behavioural inertia in starling flocks". Nature Physics. 10 (9): 615–698. arXiv:1303.7097. Bibcode:2014NatPh..10..691A. doi:10.1038/nphys3035. PMC4173114. PMID 25264452.
Further readingEdit
Khalatnikov, Isaac M. (2018). An introduction to the theory of superfluidity. CRC Press. ISBN978-0-42-997144-0.
Annett, James F. (2005). Superconductivity, superfluids, and condensates. Oxford: Oxford Univ. Press. ISBN978-0-19-850756-7.
Guénault, Tony (2003). Basic superfluids. London: Taylor & Francis. ISBN0-7484-0891-6.
Svistunov, B. V., Babaev E. S., Prokof'ev N. V. Superfluid States of Matter
Volovik, Grigory E. (2003). The Universe in a helium droplet. Int. Ser. Monogr. Phys. Vol. 117. pp. 1–507. ISBN978-0-19-850782-6.
External linksEdit
Quotations related to Superfluidity at Wikiquote
Media related to Superfluidity at Wikimedia Commons
Video: Demonstration of superfluid helium (Alfred Leitner, 1963, 38 min.)
Superfluidity seen in a 2d fermi gas recent 2021 observation relevant for Cuprate superconductors
September 05, 2023
superfluidity, confused, with, supercritical, fluid, characteristic, property, fluid, with, zero, viscosity, which, therefore, flows, without, loss, kinetic, energy, when, stirred, superfluid, forms, vortices, that, continue, rotate, indefinitely, occurs, isot. Not to be confused with supercritical fluid Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy When stirred a superfluid forms vortices that continue to rotate indefinitely Superfluidity occurs in two isotopes of helium helium 3 and helium 4 when they are liquefied by cooling to cryogenic temperatures It is also a property of various other exotic states of matter theorized to exist in astrophysics high energy physics and theories of quantum gravity 1 The theory of superfluidity was developed by Soviet theoretical physicists Lev Landau and Isaak Khalatnikov Helium II will creep along surfaces in order to find its own level after a short while the levels in the two containers will equalize The Rollin film also covers the interior of the larger container if it were not sealed the helium II would creep out and escape The liquid helium is in the superfluid phase A thin invisible film creeps up the inside wall of the bowl and down on the outside A drop forms It will fall off into the liquid helium below This will repeat until the cup is empty provided the liquid remains superfluid Superfluidity often co occurs with Bose Einstein condensation but neither phenomenon is directly related to the other not all Bose Einstein condensates can be regarded as superfluids and not all superfluids are Bose Einstein condensates citation needed Contents 1 Superfluidity of liquid helium 2 Ultracold atomic gases 3 Superfluids in astrophysics 4 In high energy physics and quantum gravity 5 See also 6 References 7 Further reading 8 External linksSuperfluidity of liquid helium EditMain article Superfluid helium 4 Superfluidity was discovered in helium 4 by Pyotr Kapitsa 2 and independently by John F Allen and Don Misener 3 in 1937 Onnes possibly observed the superfluid phase transition on August 2 1911 the same day that he observed superconductivity in mercury 4 It has since been described through phenomenology and microscopic theories In liquid helium 4 the superfluidity occurs at far higher temperatures than it does in helium 3 Each atom of helium 4 is a boson particle by virtue of its integer spin A helium 3 atom is a fermion particle it can form bosons only by pairing with another particle like itself at much lower temperatures The discovery of superfluidity in helium 3 was the basis for the award of the 1996 Nobel Prize in Physics 1 This process is similar to the electron pairing in superconductivity Ultracold atomic gases EditSuperfluidity in an ultracold fermionic gas was experimentally proven by Wolfgang Ketterle and his team who observed quantum vortices in lithium 6 at a temperature of 50 nK at MIT in April 2005 5 6 Such vortices had previously been observed in an ultracold bosonic gas using rubidium 87 in 2000 7 and more recently in two dimensional gases 8 As early as 1999 Lene Hau created such a condensate using sodium atoms 9 for the purpose of slowing light and later stopping it completely 10 Her team subsequently used this system of compressed light 11 to generate the superfluid analogue of shock waves and tornadoes 12 These dramatic excitations result in the formation of solitons that in turn decay into quantized vortices created far out of equilibrium in pairs of opposite circulation revealing directly the process of superfluid breakdown in Bose Einstein condensates With a double light roadblock setup we can generate controlled collisions between shock waves resulting in completely unexpected nonlinear excitations We have observed hybrid structures consisting of vortex rings embedded in dark solitonic shells The vortex rings act as phantom propellers leading to very rich excitation dynamics Lene Hau SIAM Conference on Nonlinear Waves and Coherent StructuresSuperfluids in astrophysics EditThe idea that superfluidity exists inside neutron stars was first proposed by Arkady Migdal 13 14 By analogy with electrons inside superconductors forming Cooper pairs because of electron lattice interaction it is expected that nucleons in a neutron star at sufficiently high density and low temperature can also form Cooper pairs because of the long range attractive nuclear force and lead to superfluidity and superconductivity 15 In high energy physics and quantum gravity EditMain article Superfluid vacuum theory Superfluid vacuum theory SVT is an approach in theoretical physics and quantum mechanics where the physical vacuum is viewed as superfluid The ultimate goal of the approach is to develop scientific models that unify quantum mechanics describing three of the four known fundamental interactions with gravity This makes SVT a candidate for the theory of quantum gravity and an extension of the Standard Model It is hoped that development of such theory would unify into a single consistent model of all fundamental interactions and to describe all known interactions and elementary particles as different manifestations of the same entity superfluid vacuum On the macro scale a larger similar phenomenon has been suggested as happening in the murmurations of starlings The rapidity of change in flight patterns mimics the phase change leading to superfluidity in some liquid states 16 Light behaves like a superfluid in various applications such as Poisson s Spot As the liquid helium shown above light will travel along the surface of an obstacle before continuing along its trajectory Since light is not affected by local gravity its level becomes its own trajectory and velocity Another example is how a beam of light travels through the hole of an aperture and along its backside before diffraction See also EditBoojum superfluidity Condensed matter physics Macroscopic quantum phenomena Quantum hydrodynamics Slow light Superconductivity SupersolidReferences Edit a b The Nobel Prize in Physics 1996 Advanced Information www nobelprize org Retrieved 2017 02 10 Kapitza P 1938 Viscosity of Liquid Helium Below the l Point Nature 141 3558 74 Bibcode 1938Natur 141 74K doi 10 1038 141074a0 S2CID 3997900 Allen J F Misener A D 1938 Flow of Liquid Helium II Nature 142 3597 643 Bibcode 1938Natur 142 643A doi 10 1038 142643a0 S2CID 4135906 van Delft Dirk Kes Peter 2010 09 01 The discovery of superconductivity Physics Today 63 9 38 43 doi 10 1063 1 3490499 ISSN 0031 9228 MIT physicists create new form of matter mit edu 22 June 2005 Retrieved November 22 2010 Grimm R 2005 Low temperature physics A quantum revolution Nature 435 7045 1035 1036 Bibcode 2005Natur 435 1035G doi 10 1038 4351035a PMID 15973388 S2CID 7262637 Madison K Chevy F Wohlleben W Dalibard J 2000 Vortex Formation in a Stirred Bose Einstein Condensate Physical Review Letters 84 5 806 809 arXiv cond mat 9912015 Bibcode 2000PhRvL 84 806M doi 10 1103 PhysRevLett 84 806 PMID 11017378 S2CID 9128694 Burnett K 2007 Atomic physics Cold gases venture into Flatland Nature Physics 3 9 589 Bibcode 2007NatPh 3 589B doi 10 1038 nphys704 Hau L V Harris S E Dutton Z Behroozi C H 1999 Light speed reduction to 17 metres per second in an ultracold atomic gas Nature 397 6720 594 598 Bibcode 1999Natur 397 594V doi 10 1038 17561 S2CID 4423307 Lene Hau Physicscentral com Retrieved 2013 02 10 Hau Lene Vestergaard 2003 Frozen Light PDF Scientific American 44 51 Hau Lene September 9 12 2006 Shocking Bose Einstein Condensates with Slow Light SIAM org Society for Industrial and Applied Mathematics A B Migdal 1959 Superfluidity and the moments of inertia of nuclei Nucl Phys 13 5 655 674 Bibcode 1959NucPh 13 655M doi 10 1016 0029 5582 59 90264 0 A B Migdal 1960 Superfluidity and the Moments of Inertia of Nuclei Soviet Phys JETP 10 5 176 Bibcode 1959NucPh 13 655M doi 10 1016 0029 5582 59 90264 0 U Lombardo amp H J Schulze 2001 Superfluidity in Neutron Star Matter Physics of Neutron Star Interiors Lecture Notes in Physics Vol 578 pp 30 53 arXiv astro ph 0012209 doi 10 1007 3 540 44578 1 2 ISBN 978 3 540 42340 9 S2CID 586149 Attanasi A Cavagna A Del Castello L Giardina I Grigera T S Jelic A Melillo S Parisi L Pohl O Shen E Viale M 2014 Information transfer and behavioural inertia in starling flocks Nature Physics 10 9 615 698 arXiv 1303 7097 Bibcode 2014NatPh 10 691A doi 10 1038 nphys3035 PMC 4173114 PMID 25264452 Further reading EditKhalatnikov Isaac M 2018 An introduction to the theory of superfluidity CRC Press ISBN 978 0 42 997144 0 Annett James F 2005 Superconductivity superfluids and condensates Oxford Oxford Univ Press ISBN 978 0 19 850756 7 Guenault Tony 2003 Basic superfluids London Taylor amp Francis ISBN 0 7484 0891 6 Svistunov B V Babaev E S Prokof ev N V Superfluid States of Matter Volovik Grigory E 2003 The Universe in a helium droplet Int Ser Monogr Phys Vol 117 pp 1 507 ISBN 978 0 19 850782 6 External links Edit nbsp Quotations related to Superfluidity at Wikiquote nbsp Media related to Superfluidity at Wikimedia Commons Video Demonstration of superfluid helium Alfred Leitner 1963 38 min Superfluidity seen in a 2d fermi gas recent 2021 observation relevant for Cuprate superconductors Retrieved from https en wikipedia org w index php title Superfluidity amp oldid 1170775913, wikipedia, wiki, book, books, library,
