其他凝聚态物理
We construct a generalized transfer matrix corresponding to noninteracting tight-binding lattice models, which can subsequently be used to compute the bulk bands as well as the edge states. Crucially, our formalism works even in cases where…
We study the lowest energy configurations of an equimolar binary mixture of classical pointlike particles with charges $Q_1$ and $Q_2$, such that $q=Q_2/Q_1\in [0,1]$. The particles interact pairwisely via 3D Coulomb potential and are…
The first two successful predictions for amorphous solid experiments by tunneling-two-level-system (TTLS) was phonon echo and saturation phenomena. In this paper by generalizing TTLS to infinite-level-system model with certain randomness…
We compute the zero-temperature dynamical structure factor of one-dimensional liquid $^4$He by means of state-of-the-art Quantum Monte Carlo and analytic continuation techniques. By increasing the density, the dynamical structure factor…
We investigate the behavior of the kinetic and the exchange energy densities near the nuclear cusp of atomic systems. Considering hydrogenic orbitals, we derive analytical expressions near the nucleus, for single shells, as well as in the…
Semilocal density functional theory is the most used computational method for electronic structure calculations in theoretical solid-state physics and quantum chemistry of large systems, providing good accuracy with a very attractive…
We have carried out a microscopic study of the dynamic structure factor of liquid $^4$He across the normal-superfluid transition temperature using the path integral Monte Carlo method. The ill-posed problem of the inverse Laplace transform,…
We discuss the polarization dynamics during solid effect dynamic nuclear polarization (DNP) in a central spin model that consists of an electron surrounded by many nuclei. To this end we use a recently developed formalism and validate first…
The polarization charge $\rho $ of an inhomogeneous superfluid system is expressed as a function of the order parameter $\Phi ({{\mathbf{r}}_{1}},{{\mathbf{r}}_{2}})$. It is shown that if the order parameter changes on macroscopic…
The formal basis for fully relativistic Korringa-Kohn-Rostoker (KKR) or multiple scattering calculations for the electronic Green function in case of a general potential is discussed. Simple criteria are given to identify situations that…
The 1/r Coulomb potential is calculated for a two dimensional system with periodic boundary conditions. Using polynomial splines in real space and a summation in reciprocal space we obtain numerically optimized potentials which allow us…
Clean Si(111)-(7{x7) surfaces, followed by air-exposure, have been investigated by reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Fourier transforms (FTs) of STM images show the presence of…
The Hofstadter butterfly is a quantum fractal with a highly complex nested set of gaps, where each gap represents a quantum Hall state whose quantized conductivity is characterized by topological invariants known as the Chern numbers. Here…
Tunable spin correlations are found to arise between two neighboring trapped exciton-polariton condensates which spin-polarize spontaneously. We observe a crossover from an antiferromagnetic- to a ferromagnetic pair state by reducing the…
We discuss a way to exploit the conformal mapping to study the response of a finite metallic element of arbitrary shape to an external electromagnetic field at finite frequencies. This provides a simple way to study different physics issues…
Integral identities for particular Bloch functions in finite periodic systems are derived. All following statements are proven for a finite domain consisting of an integer number of unit cells. It is shown that matrix elements of particular…
Theoretical and experimental results for in-plane vibrations of a uniform rectangular plate with free boundary conditions are obtained. The experimental setup uses electromagnetic-acoustic transducers and a vector network analyzer. The…
The new model of phonon transmission across the interface between two crystals is proposed featured by taking into account the mismatch of crystal lattices. It has been found that the mismatch of lattices results in phonon scattering at the…
A recent claim of possible superfluid behaviour of parahydrogen films intercalated within a crystalline matrix of Na atoms is examined. Quantum Monte Carlo simulations at finite temperature yield strong numerical evidence that the system…
We report clear experimental signatures of the theoretically unexpected gas-liquid transition in the first three monolayers of $^3$He adsorbed on graphite. The transition is inferred from the linear density dependence of the…