Related papers: The fraction of Bose-Einstein condensed triplons i…
We examine the consequences of a recent model describing correlated zero-point polarization of the electronic cloud in solid $^3$He. This polarization arises from the highly anisotropic and correlated dynamic mixing of the $s$ and $p$…
We present a comprehensive study aimed at elucidating the complex magnetic correlations in Co$_2$TiSi$_{0.5}$Al$_{0.5}$ Heusler alloy having the partial B2-type structure amid L2$_1$ cubic main phase. The thermo-magnetization measurements…
We experimentally investigate magnetocaloric effect for the topological magnetic Weyl semimetal Co$_3$Sn$_2$S$_2$ in a wide temperature range. The isothermal magnetic entropy change $\Delta S$ is calculated from the experimental…
We compute the shift of the transition temperature for a homogenous weakly interacting Bose gas in leading order in the scattering length a for given particle density n. Using variational perturbation theory through six loops in a classical…
In the first part we discuss how the BEC picture for magnons is modified by anisotropies induced by spin-orbit coupling. In particular we focus on the effects of antisymmetric spin interactions and/or a staggered component of the $g$…
The electromagnetic properties of the tetraquark state $Z_c(3900)$ are investigated in the diquark-antidiquark picture and its magnetic and quadrupole moments are extracted. To this end, the light-cone QCD sum rule in electromagnetic…
The superconducting transition temperature, $T_c$, of a ferromagnet (F) - superconductor (S) - ferromagnet trilayer depends on the mutual orientation of the magnetic moments of the F layers. This effect has been previously observed in F/S/F…
We study topological properties of one-triplon bands in an extended Shastry-Sutherland model relevant for the frustrated quantum magnet SrCu_2(BO_3)_2. To this end perturbative continuous unitary transformations are applied about the…
We have studied the impact of the magnetic field on the electromagnon excitations in TbMnO3 crystal. Applying magnetic field along the c axis, we show that the electromagnons transform into pure antiferromagnetic modes, losing their polar…
The possibility of Bose-Einstein condensation of excitations has been discussed for a long time. The phenomenon of the phase-coherent precession of magnetization in superfluid 3He and the related effects of spin superfluidity are based on…
We have investigated the magnetic properties of carbon powders which consist of nanodisks, nanocones, and a small fraction of carbon-black particles. Magnetization measurements were carried out using a superconducting quantum interference…
We synthesized single crystals of composition Ba$_2$CuSi$_2$O$_6$Cl$_2$ and investigated its quantum magnetic properties. The crystal structure is closely related to that of the quasi-two-dimensional (2D) dimerized magnet BaCuSi$_2$O$_6$…
Besides being an ancient pigment, BaCuSi$_2$O$_6$ is a quasi-2D magnetic insulator with a gapped spin dimer ground state. The application of strong magnetic fields closes this gap creating a gas of bosonic spin triplet excitations called…
Earlier, the linear magnetoelectric effect of chromium sesquioxide Cr_2 O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2 O_3 crystals or the magnetic…
The quantum phase transitions induced by a magnetic field are theoretically studied in a frustrated two-leg spin ladder. Using the density-matrix renormalization-group method, we find some magnetic phase transitions and plateaux in two…
We report results of a three dimensional, high resolution (up to 512^3) numerical investigation of supersonic compressible magnetohydrodynamic turbulence. We consider both forced and decaying turbulence. The model parameters are appropriate…
We report on the computation of the shift of the Bose-Einstein condensation temperature for a homogenous weakly interacting Bose gas in leading order in the diluteness parameter a n^(1/3), where `a' is the scattering length and `n' is the…
A full energy spectrum, magnetization and susceptibility of a spin-1/2 Heisenberg model on two edge-shared tetrahedra are exactly calculated by assuming two different coupling constants. It is shown that a ground state in zero field is…
To study the relationship between the properties of low-dimensional spin systems with weakly coupled Cu-triangles and their crystal structure, single crystals of $Cs_3Cu_3Cl_8OH$ (1) and the new $Cs_3Cu_3Cl_{7.6}Br_{0.4}OH$ (2) were grown.…
We discuss the application of Bose-Einstein condensates (BECs) as sensors for magnetic and electric fields. In an experimental demonstration we have brought one-dimensional BECs close to micro-fabricated wires on an atom chip and thereby…