Related papers: Electrical effects in superfluid helium. I. Thermo…
The transition mechanism of metal-insulator in metal oxides is discussed in detail, which is a part of the mechanism of superconductivity. Through the study of magic angle twisted bilayer graphene superconductor and other new findings on…
The recent report of the observation of Bose-Einstein condensation in atomic Hydrogen, characterized by an "anomalous" density spectrum, is shown to be in agreement with the prediction of the existence of two condensates for temperatures…
The thermal friction force acting on an atom moving relative to a thermal photon bath has recently been calculated on the basis of the fluctuation-dissipation theorem. The thermal fluctuations of the electromagnetic field give rise to a…
We study the interaction between gravitational waves and quantum matter such as Bose-Einstein condensates, super-fluid Helium, or ultra-cold solids, explicitly taking into account the changes of the trapping potential induced by the…
We numerically investigate a condensate of $^{87}$Rb atoms in an F=1 hyperfine state confined in an optical dipole trap. Assuming the magnetic moments of all atoms are initially aligned along the magnetic field we observe, after the field's…
Thermodynamic fluctuation theory originated with Einstein who inverted the relation $S=k_B\ln\Omega$ to express the number of states in terms of entropy: $\Omega= \exp(S/k_B)$. The theory's Gaussian approximation is discussed in most…
Measurement techniques based upon the Hall effect are invaluable tools in condensed matter physics. When an electric current flows perpendicular to a magnetic field, a Hall voltage develops in the direction transverse to both the current…
Crystalline solids are generally known as excellent heat conductors, amorphous materials or glasses as thermal insulators. It has thus come as a surprise that certain crystal structures defy this paradigm. A prominent example are type-I…
Electrons trapped on the surface of liquid helium is an extremely clean system which holds promise for a scalable qubit platform. However, the superfluid surface is not free from fluctuations which might cause the decay and dephasing of the…
An attempt is made to explain the nature of the electric signal observed in He II in a second-sound standing wave. Using the general quantum-mechanical principles, we show that, due to interatomic interaction, each atom of He-II acquires a…
The possibility of a supersolid state of matter, i.e., a crystalline solid exhibiting superfluid properties, first appeared in theoretical studies about forty years ago. After a long period of little interest due to the lack of experimental…
The work of Ahn derives the noise power spectrum of a two-level fluctuator (TLF) in the case that it interacts only with a subregion of a full electron bath and thus is subject to a fluctuating temperature. However, Eq.~(1), which gives the…
Matter at low temperatures exhibits unusual properties such as superfluidity, superconductivity, Bose-Einstein condensation, and supersolidity. These states display quantum mechanical behaviours at scales much larger than atomic dimensions.…
The theory of hole superconductivity predicts that in superconductors the charged superfluid is about a million times more rigid than the normal electron fluid. We point out that this physics should give rise to large changes in the bulk…
Almost a century ago, Johnson and Nyquist presented evidence of fluctuating electrical current and the governing fluctuation dissipation theorem (FDT). Whether, likewise, temperature T can fluctuate is a controversial topic and has led to…
We investigate the new type of excitations on the surface of liquid helium. These excitations, called surfons, appear because helium atoms have discrete energy level at the liquid surface, being attracted to the surface by the van der Waals…
We report a study of the intensity and time dependence of scintillation produced by weak alpha particle sources in superfluid helium in the presence of an electric field (0 - 45 kV/cm) in the temperature range of 0.2 K to 1.1 K at the…
We report hot-wire measurements performed in two very different, co- and counter-rotating flows, in normal and superfluid helium at 1.6 K, 2 K, and 2.3 K. As recently reported, the power spectrum of the hot-wire signal in superfluid flows…
An experiment is proposed to test a previously developed theory of the hydrodynamics of a nonequilibrium heat current-induced superfluid-normal interface. It is shown that the interfacial ``trapped'' second sound mode predicted by the…
Matter-wave interferometers reveal some of the most fascinating phenomena of the quantum world. Phase shifts due to rotation (the Sagnac effect) for neutrons, free atoms and superfluid 3He reveal the connection of matter waves to a…