Related papers: Order-disorder transition in nanoscopic semiconduc…
The effect of short-range disorder in nodal line semimetals is studied by numerically exact means. For arbitrary small disorder, a novel semimetallic phase is unveiled for which the momentum-space amplitude of the ground-state wave function…
We study quantum corrections to conductivity in a 2D system with a smooth random potential and strong spin-orbit splitting of the spectrum. We show that the interference correction is positive and down to the very low temperature can exceed…
Wigner crystals are prime candidates for the realization of regular electron lattices under minimal requirements on external control and electronics. However, several technical challenges have prevented their detailed experimental…
The quasi-one-dimensional S=1 Heisenberg antiferromagnet with a biquadratic term is investigated at zero temperature by quantum Monte Carlo simulation. As the magnitude of the inter-chain coupling is increased, the system undergoes a phase…
We consider a system of superconducting grains embedded in a normal metal. At zero temperature this system exhibits a quantum superconductor-normal metal phase transition. This transition can take place at arbitrarily large conductance of…
We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect and the conductance reaches the unitary-limit…
We find an analytical expression for the conductance of a single electron transistor in the regime when temperature, level spacing, and charging energy of a grain are all of the same order. We consider the model of equidistant energy levels…
We study the S>1 nearest-neighbor Heisenberg model with a ferromagnetic interaction J and a large non-collinear <111> easy-axis anisotropy D on a pyrochlore lattice. For a finite D>>|J|, the low-energy physics is described by a < 111 >…
We develop an efficient numerical method to study the quantum critical behavior of disordered systems with $\mathcal{O}(N)$ order-parameter symmetry in the large$-N$ limit. It is based on the iterative solution of the large$-N$ saddle-point…
We study the onset of spin-density wave order in itinerant electron systems via a two-dimensional lattice model amenable to numerically exact, sign-problem-free determinantal quantum Monte Carlo simulations. The finite-temperature phase…
Quantum spin rings represent fundamental model systems that exhibit distinctive quantum phenomena-such as quantum critical behavior and quasiparticle excitations-arising from their periodic boundary conditions and enhanced quantum…
Using low-energy electron diffraction, we show that the room-temperature $(\sqrt{2}\times\sqrt{2})R45^\circ$ reconstruction of Fe$_3$O$_4$(100) reversibly disorders at $\sim$450 $^\circ$C. Short-range order persists above the transition,…
When a strong magnetic field is applied perpendicularly (along z) to a sheet confining electrons to two dimensions (x-y), highly correlated states emerge as a result of the interplay between electron-electron interactions, confinement and…
We investigate the Kondo effect in two-dimensional disordered electron systems using a finite-temperature quantum Monte Carlo method. Depending on the position of a magnetic impurity, the local moment is screened or unscreened by the spin…
The physics of interacting quantum wires has attracted a lot of attention recently. When the density of electrons in the wire is very low, the strong repulsion between electrons leads to the formation of a Wigner crystal. We review the rich…
We present a theoretical survey of ferromagnetic transition temperatures in cubic (III,Mn)V semiconductors based on a model with $S=5/2$ local moments exchange-coupled to itinerant holes in the host semiconductor valence band. Starting from…
Absorption of circularly polarized light in semiconductors is known to result in optical orientation of electron and hole spins. It has been shown here that in semiconductor quantum well structures spin orientation of carriers can be…
Quantum spin rings represent an intriguing platform for studying unconventional magnetic order and exotic quantum phases, and they are also promising materials for emerging quantum technologies. Conventional spin systems consist of a set of…
We investigate the disorder-driven superconductor to insulator quantum phase transition (SIT) in an interacting fermion model using determinantal quantum Monte Carlo (QMC) methods. The disordered superconductor is modeled by an attractive…
We present a variational method to calculate the exchange interactions among donor clusters in a semiconductor. Such clusters are candidates for a so-called control-qubit architecture for quantum information, where the effective exchange…