相关论文: Quantum melting a Wigner crystal into Hall liquids
The two-dimensional Wigner crystals are studied with the variational quantum Monte Carlo method. The close relationship between the ground-state wavefunction and the collective excitations in the system is illustrated, and used to guide the…
We compare the free energy computed from the ground state energy and low-lying excitations of the 2-D Wigner solid and the fractional quantum Hall liquid, at magnetic filling factors $\nu = 1/7$ and 1/9. We find that the Wigner solid melts…
A two-dimensional crystal melts via the proliferation and unbinding of topological defects, yet quantitatively predicting the melting temperature $T_m$ in real systems is challenging. Here we resolve this discrepancy in quantum Hall…
Wigner crystallization can be induced in a quantum dot by increasing the effective electron-electron interaction through a decrease of the electron density or by the application of a strong magnetic field. We show that the ground state in…
The phase diagram of quantum electron bilayers in zero magnetic field is obtained using density functional theory. For large electron densities the system is in the liquid phase, while for smaller densities the liquid may freeze (Wigner…
A two-dimensional array of quantum dots in a magnetic field is considered. The electrons in the quantum dots are described as unitary random matrix ensembles. The strength of the magnetic field is such that there is half a flux quantum per…
Spin splitting in the integer quantum Hall effect is investigated for a series of Al$_{x}$Ga$_{1-x}$As/GaAs heterojunctions and quantum wells. Magnetoresistance measurements are performed at mK temperature to characterize the electronic…
We present the first microscopic demonstration of a disorder-pinned hole Wigner crystal (WC), providing a natural explanation for the reentrant integer quantum Hall effect observed near $\nu=2/3$, as well as its analogs in fractional Chern…
The quantum Hall liquid is a novel state of matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external…
In this report, we study ultra-high-mobility two-dimensional (2D) electron/hole systems with high precision capacitance measurement. We find that the capacitance charge appears only at the fringe of the gate at high magnetic field when the…
Eugene Wigner predicted long ago that when the Coulomb interactions between electrons become much stronger than their kinetic energy, electrons crystallize into a closely packed lattice. A variety of two-dimensional systems have shown…
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…
From the Fractional Quantum Hall Effect States on a torus with filling factor nu = 1/p, p odd, we found that for small values of nu such states describe triangular Wigner crystals which are stable configurations. Therefore, the insulator…
The interplay between strongly correlated liquid and crystal phases for two-dimensional electrons exposed to a high transverse magnetic field is of fundamental interest. Through the non-perturbative fixed phase diffusion Monte Carlo method,…
We study the quantum melting of the two-dimensional Wigner crystal using a fixed node quantum Monte-Carlo approach. In addition to the two already known phases (Fermi liquid at large density and Wigner crystal at low density), we find a…
The melting of a Wigner Crystal of electrons placed into a host polar material is examined as a function of the density and the temperature. When the coupling to the longitudinal optical modes of the host medium is turned on, the WC is…
We report an extensive Monte-Carlo study of the melting of the classical two dimensional Wigner crystal for a system of point particles interacting via the $1/r$-Coulomb potential. A hexatic phase is found in systems large enough. With the…
We study the Wigner crystal melting in a two dimensional quantum system of particles interacting via the 1/r Coulomb potential. We use quantum Monte Carlo methods to calculate its phase diagram, locate the Wigner crystal region, and analyze…
We study the localization properties in the transition from a two-dimensional electron gas at zero magnetic field into an integer quantum Hall (QH) liquid. By carrying out a direct calculation of the localization length for a finite size…
Wigner crystallization of electrons in a 2D quantum dots is reported. It proceeds in two stages: I) via radial ordering of electrons on shells and II) freezing of the inter-shell rotation. The phase boundary of the crystal is computed in…