相关论文: Quantum Glass Transition in a Periodic Long-Range …
Ising spin glasses in a transverse field exhibit a zero temperature quantum phase transition, which is driven by quantum rather than thermal fluctuations. They constitute a universality class that is significantly different from the…
We investigate the ground-state properties of quantum particles interacting via a long-range repulsive potential ${\cal V}_\sigma(x)\sim 1/|x|^{1+\sigma}$ ($-1<\sigma$) or ${\cal V}_\sigma(x)\sim -|x|^{-1-\sigma}$ ($-2\leq \sigma <-1$) that…
For magnets with a fully frustrated inter-layer interaction, we argue that the quantum phase transitions from a paramagnetic to an antiferromagnetic ground state, driven by pressure or magnetic field, are asymptotically three-dimensional,…
We consider the disordered quantum rotor model in the presence of a magnetic field. We analyze the transport properties in the vicinity of the multicritical point between the superconductor, phase glass and paramagnetic phases. We find that…
We study the zero-temperature phase transitions of two-dimensional superconducting arrays with both the self- and the junction capacitances in the presence of external magnetic fields. We consider two kinds of excitations from the Mott…
Large fluctuations of conductivity with time are observed in a low-mobility two-dimensional electron system in silicon at low electron densities $n_s$ and temperatures. A dramatic increase of the noise power ($\propto 1/f^{\alpha}$) as…
The experiments performed with neutral atoms trapped in optical tweezers and coherently coupled to the Rydberg state allow quantum simulations of paradigmatic Hamiltonians for quantum magnetism. Previous studies have focused mainly on…
A superglass is a phase of matter which is characterized at the same time by superfluidity and a frozen amorphous structure. We introduce a model of interacting bosons in three dimensions that displays this phase unambiguously and that can…
We analyze the ground state properties of an array of quantum dots connected in series between superconducting electrodes. This system is represented by a finite Hubbard chain coupled at both ends to BCS superconductors. The ground state is…
We investigate the quantum phase transitions in two capacitively coupled chains of ultra-small Josephson-junctions, with emphasis on the external charge effects. The particle-hole symmetry of the system is broken by the gate voltage applied…
As the size of a Josephson junction is reduced, charging effects become important and the superconducting phase across the link turns into a periodic quantum variable. Isolated Josephson junction arrays are described in terms of such…
We study the effect of random offset charges in the insulator to conductor transition in systems of capacitively coupled grains, as realized in two-dimensional arrays of ultrasmall Josephson junctions. In presence of disorder, the…
An effective free energy of a two dimensional (i.e. large area) Josephson Junctions is derived, allowing for thermal fluctuations, for random magnetic fields and for external currents. We show by using replica symmetry breaking methods,…
Numerical simulations of the current-voltage characteristics of an ordered two-dimensional Josephson junction array at an irrational flux quantum per plaquette are presented. The results are consistent with an scaling analysis which assumes…
We probe through magnetization and resistivity measurements a kinetically arrested glass-like but long-range ordered magnetic state. The transformation kinetics of the magnetic field-temperature induced broad first-order transition from…
The quantum critical behavior of the Ising glass in a magnetic field is investigated. We focus on the spin glass to paramagnet transition of the transverse degrees of freedom in the presence of finite longitudinal field. We use two…
We study the zero-temperature phase diagram of a dissipationless and disorder-free Josephson junction chain. Namely, we determine the critical Josephson energy below which the chain becomes insulating, as a function of the ratio of two…
We examine the effects of disorder on dimerized quantum antiferromagnets in a magnetic field, using the mapping to a lattice gas of hard-core bosons with finite-range interactions. Combining a strong-coupling expansion, the replica method,…
A quantum system can undergo a continuous phase transition at the absolute zero of temperature as some parameter entering its Hamiltonian is varied. These transitions are particularly interesting for, in contrast to their classical finite…
We carry out extensive Monte Carlo simulations on the Coulomb gas dual to the uniformly frustrated two dimensional XY model, for a sequence of frustrations f converging to the irraltional (3-sqrt 5)/2. We find in these systems a sharp first…