相关论文: Geometric Percolation Threshold Defines Half-Metal…
Superconductivity in the topological non-trivial Dirac semimetal PdTe$_2$ was recently shown to be type-I. We here report measurements of the relative magnetic penetration depth, $ \Delta \lambda$, on several single crystals using a high…
The double perovskite material \SFMO has the rare and desirable combination of a half-metallic ground state with 100% spin polarization and ferrimagnetic \Tc$\simeq 420$K, well above room temperature. In this two-part paper, we present a…
The topology of Weyl semimetals requires the existence of unique surface states. Surface states have been visualized in spectroscopy measurements, but their connection to the topological character of the material remains largely unexplored.…
We describe the behavior of a system of fermionic atoms loaded in a bipartite one-dimensional optical lattice that is under the action of an external time-periodic driving force. By using Floquet theory, an effective model with renormalized…
Nanogranular metal composites, consisting of immiscible metallic and insulating phases deposited on a substrate, are characterized by two distinct electronic transport regimes depending on the relative amount of the metallic phase. At…
We investigate the striking absence of strong localisation observed in mesoscopic two-dimensional electron gases (2DEGs) (Baenninger et al 2008 Phys. Rev. Lett. 100 1016805, Backes et al 2015 Phys. Rev. B 92 235427) even when their…
We present the technical details of an experimental method to realize a model system for 2D phase transitions and the glass transition. The system consists of several hundred thousand colloidal super-paramagnetic particles confined by…
The breaking of time-reversal symmetry by ferromagnetism is predicted to yield profound changes to the electronic surface states of a topological insulator. Here, we report on a concerted set of structural, magnetic, electrical and…
We study a two-band Hubbard model using the dynamical mean-field theory combined with the exact diagonalization method. At the electron density $n=2$, a transition from a band-insulator to a correlated semimetal occurs when the on-site…
In many composites the electrical transport takes place only by tunneling between isolated particles. For a long time it was quite a puzzle how, in spite of the incompatibility of tunneling and percolation networks, these composites conform…
A Metal-Disordered Mott insulator-Metal heterostructure is studied at half-fiiling using unrestricted Hartree Fock method. The corresponding clean system has been shown to be an insulator for any finite on site correlation. Interestingly we…
Recent thermodynamic measurements on two-dimensional (2D) electron systems have found diverging behavior in the magnetic susceptibility and appearance of ferromagnetism with decreasing electron density. The critical densities for these…
Two-dimensional (2D) semimetals beyond graphene have been relatively unexplored in the atomically-thin limit. Here we introduce a facile growth mechanism for semimetallic WTe2 crystals, then fabricate few-layer test structures while…
Moir\'e superlattices formed in two-dimensional semiconductor heterobilayers provide a new realization of Hubbard model physics in which the number of electrons per effective atom can be tuned at will. We report on an exact diagonalization…
The critical electron density for the metal-insulator transition in a two-dimensional electron gas can be determined by two distinct methods: (i) a sign change of the temperature derivative of the resistance, and (ii) vanishing activation…
We utilize a glass-like structural transition in order to induce a Mott metal-insulator transition in the quasi-two-dimensional organic charge-transfer salt $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Br. In this material, the terminal ethylene…
Two phenomena have been recently observed in high-mobility Si MOS structures: (1) strong enhancement of the metallic conduction at low temperatures, T < 2K, and (2) the scaling behavior of the temperature and electric field dependences of…
Unusual metallic states involving breakdown of the standard Fermi-liquid picture of long-lived quasiparticles in well-defined band states emerge at low temperatures near correlation-driven Mott transitions. Prominent examples are…
Suitable cluster definitions have allowed researchers to describe many ordering transitions in spin systems as geometric phenomena related to percolation. For spin glasses and some other systems with quenched disorder, however, such a…
The diverse electronic properties of transition metal chalcogenides can be very sensitive to crystal imperfections. A new crystal growth technique, known as horizontal flux transport, offers a route to improved crystal quality. By refining…