Superfluid State, Quantum fluids, including superfluids and superconductors, exhibit exotic properties like frictionless flow and zero resistance, with applications in quantum computing, precision sensing, and energy efficiency. The lambda point is the temperature at which normal fluid helium (helium I) makes the transition to superfluid state (helium II). Because it could flow without friction, superfluid helium climbed the walls of its container and dripped over the sides. Superfluid vacuum theory (SVT), sometimes known as the BEC vacuum theory, is an approach in theoretical physics and quantum mechanics where the fundamental physical vacuum (non-removable background) is considered as a superfluid or as a Bose–Einstein condensate (BEC). The transition to the superfluid state requires breaking residual intermolecular bonds, which consumes energy and lowers the temperature, causing the transition to span a range rather than occurring at a constant temperature. Therefore, unlike electrons, multiple Cooper pairs are allowed to be in the same quantum state, which is responsible for the phenomenon of superconductivity. 15 °C, or −459. The resulting $T_c$ curves show that the enhancement of pairing due to the SOC roughly cancels out the suppression of pairing due to the population imbalance. The thermal conductivity of superfluid helium II is more that a million times greater than that of liquid helium I, and helium II is a better conductor of heat than any metal. Superfluid phase at temperature below 2. Upon further cooling, increasing amounts of the helium are converted to the superfluid state. Meet one of the strangest substances in the universe: a superfluid. Thus, there are no gas bubbles in the body of the liquid. In other words, 3 He is an anisotropic superfluid, rather than exhibiting the isotropic pairing state described by BCS theory. There exists some connection between superconductors and superfluids. Both of them are super-interesting to study:-) Superfluid is a low-temperature state of a quantum many-body system of electrically neutral particles (e. The superfluid state of a liquid, first of all, is characterized with its ability to flow through the thin capillaries without any friction, displaying no viscous effects typical for viscid normal liquid. This has been suggested as an explanation for the observed sudden changes in the rotation velocity of pulsars. Isotope fractionation occurs during a phase transition, the ratio of light to heavy isotopes in the involved molecules changes. A superfluid displays zero viscosity. We report direct experimental signatures for the spin superfluid ground state in canted antiferromagnets via nonlocal spin transport. 17 K (−270. 17 K. By Pauli's exclusion principle, the ground state of a Fermi gas consists of fermions occupying all momentum states corresponding to momentum with all higher momentum states unoccupied. In physics, a state of matter or phase of matter is one of the distinct forms in which matter can exist. A practical guide to micropayments in DeFi — Lightning Network, state channels, Layer-2 options, streaming money protocols and business use cases. Superfluids can be liquids or gases, but not We found that in such inertially driven turbulence, regardless of the normal or superfluid state of the fluid, estimates of energy at the different scales are compatible with each other and consistent with oscillating grid turbulence results reported for normal fluids in the literature. The variational theory of equilibrium boson system state to have been previously developed by the author under the density matrix formalism is applicable for researching equilibrium states and thermodynamic properties of the quantum Bose gas which consists of zero-spin particles. . g. Jan 13, 2026 · A superfluid is a state of matter that flows without any friction, a property that fundamentally defies classical physics expectations. Studies could yield deeper insights into superfluids and superconductors, which are important for improvements in technologies such as superconducting magnets and sensors, as well as efficient energy transport. In physics, superfluidity is a property of fluids where they have zero viscosity or are frictionless. HELIUM AS A QUANTUM LIQUID: BOSE CONDENSATION The fact that helium does not form a solid even at T An overview of superfluidity and its mathematical modeling with the HVBK equations. It could be evidence of a superfluid transitioning into a supersolid. In each case the unusual behaviour arises from Superfluidity, the frictionless flow and other exotic behaviour observed in liquid helium at temperatures near absolute zero (−273. Early theoretical work predicted that fluctuations above the superfluid transition in liquid 3He should be observable in viscosity. <p>Superfluids are a unique state of matter that occurs at extremely low temperatures, characterized by the absence of viscosity, allowing them to flow without dissipating energy. Discover how. Superfluidity Superfluidity is a state of matter where fluid or a liquid can act very strangely. 2 K and 50 atm, solid helium-4 may be a superglass (an amorphous solid exhibiting superfluidity). Alfred Leitner video on Superfluid Helium: • Video more Learn how superfluids work, from the role of quantum mechanics to their potential applications in fields like fluid dynamics and energy production. The unusual topological superconductor LaNiGa2, currently modeled as non-unitary triplet, is used as a case study. (How easily a liquid can flow is called its viscosity. [8] The Mott insulating phases are characterized by integer boson densities, by the existence of an energy gap for particle-hole excitations, and by zero compressibility. ️🌀 When liquid helium is cooled to just above absolute zero (-271°C), it enters a quantum state with zero viscosity. The presence of two phases is a clear indication that 3 He is an unconventional superfluid (superconductor), since the presence of two phases requires an additional symmetry, other than gauge symmetry, to be broken. 15 °C, or −459. In this state, the thermal conductivity is extremely high. Baten et al. Although superfluids flow indefinitely, scientists just witnessed one stopping. Such behavior is collective, is itrelative le mot in on. ) In fact, it flows so easily that friction does not change the way it flows; it has zero viscosity. It isthat thought tthere at superfluid He II is a Bose-Einstein condensate state so that they move cooperatively. Thus the behavior of helium below its lambda point is explained in terms of a mixture of a normal component, with properties characteristic of a normal liquid, and a superfluid component. A superfluid is a phase of matter capable of flowing endlessly without losing energy. Superfluid refers to the state of matter in which the matter possesses the properties of liquid with zero viscosity. superfluidity, the frictionless flow and other exotic behaviour observed in liquid helium at temperatures near absolute zero (−273. A substance displaying this property is superfluid. In each case the unusual behaviour arises from A supersolid has an ordered structure like a solid but can also flow without friction like a superfluid, and previously they have only been produced in so-called "Bose–Einstein condensates When cooled to near absolute zero, bosons form what’s called a Bose-Einstein condensate — a superfluid state that was first co-discovered by Ketterle, and for which he was ultimately awarded the 2001 Nobel Prize in physics. 67 °F), and (less widely used) similar frictionless behaviour of electrons in a superconducting solid. In each case the unusual behaviour arises from quantum mechanical effects. This unique state occurs at extremely low temperatures, where quantum mechanical effects become significant, enabling the fluid to exhibit remarkable properties such as the ability to climb walls and flow through tiny openings without resistance. Superfluid A superfluid is a second liquid state formed by some types of matter. Abstract We consider a model of hard-core bosons on a lattice, half-filling a Chern band such that the system has a continuous transition between a fractional Chern insulator (FCI) and a superfluid state (SF) depending on the bandwidth to bandspacing ratio. This overview provides a survey of the environment of the muon, from the normal state to the superfluid state, where the induced supercurrent and Yu-Shiba-Rusinov gap states provide coupling of the muon moment to the superfluid. Connext & Raiden Generalized state channels and ERC‑20 fast transfers enable sub-cent payments and multi-hop routing across a payments graph. The superfluid transition in liquid helium is an example of this. 4. Superfluidity, the frictionless flow and other exotic behaviour observed in liquid helium at temperatures near absolute zero (−273. Particle pulse distribution function is obtained and duly employed for calculation of chemical potential, internal This suggests the second layer as a candidate for hosting two exotic quantum ground states: the spatially modulated superfluid and supersolid phases resulting from the interplay between superfluid and structural orders. Because of its extremely high thermal conductivity, the superfluid phase of helium-4 is an excellent coolant for high-field magnets, and both isotopes have some applications as detectors of exotic particles. Even if no new phases, parameters including Superfluid gap Δ are important Superfluid gap for low-density neutron matter affects cooling Benchmark for pairing in the strong-coupling QCD QCD at high densities Neutron star cooling curves Fundamental transition from weak (BCS) to strong (BEC) pairing and `exotic’ states of Hamiltonian matter Superfluidity is a phase of matter characterized by the complete absence of viscosity, allowing it to flow without dissipating energy. Landau argued that in this situation, the ground state of the Fermi gas would adiabatically transform into the ground state of the interacting system. At pressure of 1 atmosphere, the transition occurs at approximately 2. Streaming Money: Superfluid & Sablier Streaming protocols allow continuous per-second payments—useful for payroll, subscriptions and DAOs. Feb 9, 2022 · By definition, superfluidity is the zero viscosity flow of a fluid, such as a liquid or gas. The breaking of symmetries in the laws of physics during the early history of the universe as its temperature cooled. This is due to a sudden increase in the thermal conductivity of the liquid when it transitions to the superfluid state. Illustration of fermionic pairings changing from a BCS superfluid with weak coupling to those of a system of diatomic molecules When superfluid helium flows through a narrow channel, it emerges at a lower temperature: the mechanocaloric effect. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. MIT physicists have created a new form of matter, a supersolid, which combines the properties of solids with those of superfluids. You can put bosons and fermions together, and you can create a superfluid state, which is at the same time a Bose-Einstein condensate state of the bosonic part and BCS-like state of the fermionic part, for example. Closely related to this effect is a large thermomechanical effect; a temperature gradient along a narrow channel containing superfluid helium leads to a large pressure gradient. This frictionless movement means that if a superfluid were set in motion, it would continue to flow indefinitely without losing kinetic energy. Superfluid enterprises use AI and automation to eliminate friction, boost agility and unlock new competitive advantages. The normal component (gas of excitations) does interact with walls but not with superfluid part below critical velocity. The direct uses of superfluid helium are actually rather few. You can put more particles of spin up and less particles of spin down. In fact, it is a p-wave superfluid, with spin one, S = 1 ħ, and angular momentum one, L = 1 ħ. Superfluidity is a unique state of matter that occurs when certain Lambda point The plot of the specific heat capacity versus temperature. Some of the things a superfluid can do are: It can flow extremely easily. The motion of the latter has irrotational (topological) properties. atoms). This causes heat in the body of the liquid to be transferred to its surface so quickly that vaporization takes place only at the free surface of the liquid. Physicists saw excitons, a type of quasiparticle, undergo a reversible phase transition from superfluid to supersolid for the first time, opening new doors for studying extreme states of matter. The neutron liquid in a neutron star is believed to be in a superfluid state. Superfluidity occurs in two isotopes of helium (helium-3 and helium-4) when they are liquefied by cooling to cryogenic temperatures. friction) and the flow is irrotational (up to quantum vortices). Regular light behaves like a wave, and sometimes like a particle, always travelling in a straight line. The superfluid state of helium-3 reveals a complex interplay of quantum mechanics and thermodynamic principles. At absolute zero temperature the liquid is in the energetically lowest or ground state. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Within this framework, the Sarma state or the spin polarized superfluid state and polarized pseudogap state are explored in detail. Superfluids have some amazing properties. Another thing you can do is you can imbalance the system. It features different phases, showcasing variations in thermal conductivity and other properties. For example, there is no dissipation (i. After cooling the atoms, the researchers used a set of lasers to create a crystalline array of atoms, or optical lattice. 98 °C). Superfluid A linear correlation between superfluid density and T-linear resistivity coefficient is revealed in both FeSe and cuprates. 4 days ago · Although superfluids flow indefinitely, scientists just witnessed one stopping. Superfluidity was observed for helium in 1937. It is theorized that at 0. In other words, it has no resistance to flow. This phenomenon is most commonly observed in liquid helium at temperatures below approximately 2. Paired parton trial states for the superfluid-fractional Chern insulator transition Abstract: We consider a model of hard-core bosons on a lattice, half-filling a Chern band such that the system has a continuous transition between a fractional Chern insulator (FCI) and a superfluid state (SF) depending on the bandwidth to bandspacing ratio. Superfluids flow without loss of kinetic energy. Since the second law of thermodynamics states that heat cannot flow from lower to higher temperatures, this implies that the superfluid component carries no heat: any heat in the helium II must be in the normal component. e. document the reduction of the viscosity due to Liquid helium, superfluidity Conclusions of Lecture 4 Superfluidity is a complex of phenomena associated with nonzero supefluid density. Feb 6, 2026 · A superfluid freezes and breaks the rules of physics In a sheet of graphene, a superfluid has finally frozen—revealing a long-mysterious quantum state that blurs the line between solid and liquid. 2 kelvins, which exhibits unusual behaviors not predicted by classical physics, such as the ability to flow up the Phase diagram At zero temperature, the Bose–Hubbard model (in the absence of disorder) is in either a Mott insulating state at small , or in a superfluid state at large . This matter is both a superfluid, which has zero friction and viscosity, and a kind of Bose-Einstein condensate - sometimes described as the fifth state of matter - and it allows light to actually flow around objects and corners. Superfluid helium-4 Superfluid helium-4 (helium II or He-II) is the superfluid form of helium-4, the most common isotope of the element helium. 67 °F), and (less widely used) similar frictionless behaviour of electrons in a superconducting solid. Liquid helium, superfluidity The superfluid behavior is a manifestation of Bose–Einstein condensation, which occurs only in collections of bosons. [3][4][5] These microscopic quantum fluctuations can induce a macroscopic phase transition in the ground state of a many-body system when the relative strength of two competing energy terms is varied across Helium becomes superfluid and displays amazing properties. efbq, iwiw, zzvz, 3hv1o, y5ga6, om8s5, vw6f, oxpas, z6gus, vdrhy,