相关论文: Multilevel Tunnelling Systems and Fractal Clusteri…
A dynamical theory is constructed to describe spectral diffusion in glasses in the temperature range near 1 Kelvin on long time scales. The theory invokes interacting tunneling centers (TLS) which provide an excess contribution to the…
Spin glasses are frustrated magnetic systems due to a random distribution of ferro- and antiferromagnetic interactions. An experimental three dimensional (3d) spin glass exhibits a second order phase transition to a low temperature spin…
Topological Surface States (TSS) represent new types of two dimensional electron systems with novel and unprecedented properties distinct from any quantum Hall-like or spin-Hall effects. Their Z$_2$ topological order can be realized at room…
The absence of conventional magnetic order together with anomalous low-temperature magnetic heat capacity is often interpreted as evidence for quantum spin liquid ground states in frustrated magnets. Using a recently developed semiclassical…
The anomalous Hall coefficient Rs has been studied for the reentrant spin glass system Fe0.7Al0.3 by measuring the magnetization M and the Hall resistivity r_H. We have found that R_s exhibits anomalous temperature dependence at the…
Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs),…
The statistical mechanics of simple glass forming systems in 2 dimensions is worked out. The glass disorder is encoded via a Voronoi tessellation, and the statistical mechanics is performed directly in this encoding. The theory provides,…
Recently it has been experimentally demonstrated that certain glasses display an unexpected magnetic field dependence of the dielectric constant. In particular, the echo technique experiments have shown that the echo amplitude depends on…
In-situ X-ray scattering monitoring is carried out during temperature annealing on different densified SiO$_2$ glasses. Density fluctuations and intermediate range coherence from x-ray scattering (SAXS) and diffraction (WAXS) evidence a…
We study a controlled large-$N$ theory of electrons coupled to dynamical two-level systems (TLSs) via spatially-random interactions. Such a physical situation arises when electrons scatter off low-energy excitations in a metallic glass,…
We report results from Monte Carlo simulations of systems of magnetic dipoles that relax through quantum tunneling, much as Fe_8 crystals at very low temperature.For short times, a hole develops in suitably defined magnetic field…
The glass transition temperature (Tg) is the temperature, after which the supercooled liquid undergoes a dynamical arrest. Usually, the glass network modifiers (e.g., Na2O) affect the behavior of Tg. However, in aluminosilicate glasses, the…
The low temperature universal properties in disordered and amorphous solids are considered. We introduce a model that includes two types of two level systems (TLSs), which, based on their local symmetry, interact weakly or strongly with the…
The diverse quantization phenomena in 2D condensed-matter systems, being due to a uniform perpendicular magnetic field and the geometry-created lattice symmetries, are the focuses of this book. They cover the diversified magneto-electronic…
At temperatures well below their glass transition, the deformation properties of bulk metallic glasses are characterised by a sharp transition from elasticity to plasticity, a reproducible yield stress, and an approximately linear decrease…
Alkaline earth silicate glasses $xCaO-(1-x)SiO_2$ exhibit a well marked threshold in Raman lineshapes which can be related to the onset of network rigidity as the concentration of calcium oxide $x$ is decreased. The present results are…
Multiple structure and symmetry types and their transformations are discovered in quasi-two-dimensional (quasi-2D) Cr2Ge2Te6 crystal in surprisingly very narrow temperature range of 2 K and magnetic field range of 0.07 T using a homebuilt…
Topological nodal-line semimetals (TNLSs) exhibit exotic physical phenomena due to a one-dimensional (1D) band touching line, rather than discrete (Dirac or Weyl) points. While so far proposed two-dimensional (2D) TNLSs possess closed nodal…
Topological data analysis (TDA) is a new emerging and powerful tool to understand the medium range structure ordering of multi-scale data. This study investigates the density anomalies observed during cooling of liquid silica from…
The crossing of temperature dependences of the sound velocity in normal and superconducting state of metallic glasses points out unambiguously the renormalization of the intensity of sound interaction with two-level systems (TLS), caused by…