We have developed and implemented a formalism for computing the structural response of a periodic insulating system to a homogeneous static electric field within density-functional perturbation theory ~DFPT!. We consider the thermodynamic potentials E(R,h ,E) and F(R,h ,P), whose minimization with respect to the internal structural parameters R and unit cell strain h yields the equilibrium stru...

– The Mott-Hubbard transition is studied in the context of the two-dimensional Hubbard model. Analytical calculations show the existence of a critical value Uc of the potential strength which separates a paramagnetic metallic phase from a paramagnetic insulating phase. Calculations of the density of states and double occupancy show that the ground state in the insulating phase contains always a...

The quantum anomaly that breaks the symmetry, for example the parity and the chirality, in the quantization leads to a physical quantity with a topological Chern invariant. We report the observation of a Chern structure in the Bose-insulating phase of Sr2RuO4 nanofilms by employing electric transport. We observed the superconductor-to-insulator transition by reducing the thickness of Sr2RuO4 si...

We study the ground state of the two-dimensional Anderson-Hubbard model using a quantum real space renormalization group method. We obtain the phase diagram near half filling. The system is always insulating with disorder. At half filling, the system undergoes a transition from a gapless (Anderson) insulator to an incompressible (Mott-Hubbard) insulator as the interaction U reaches a critical v...

We report a new correlated phase of two-dimensional charged carriers in high magnetic fields, manifested by an anisotropic insulating behavior at low temperatures. It appears in a large range of low Landau level fillings 1/3≲ν≲2/3 in hole systems confined to wide GaAs quantum wells when the sample is tilted in magnetic field to an intermediate angle. The parallel field component (B_{∥}) leads t...

It is shown that a momentum boost technique applied to the extended Kohn-Sham scheme enables the computational determination of the Mott insulating transition. Self-consistent solutions are given for correlated electron systems by first-principles calculations defined by the multi-reference density functional theory, in which the effective short-range interaction can be determined by the fluctu...

We study the phase diagram at finite temperature of Josephson junction arrays with capacitive disorder (i.e., random offset charges and/or random charging energies): in the limit of large particle numbers per junction, this is a remarkable physical realization of the disordered boson Hubbard model. By using a mean-field approximation, we compute the average free energy and the equation for the ...

To unleash the full potential of graphene in electronics and optoelectronics, high-quality graphene patterns on insulating substrates are required. However, existing methods generally follow a "synthesis + patterning" strategy, which are time consuming and costly for fabricating high-quality graphene patterns on desired substrates. We developed a nanofabrication process to deposit high-quality ...

Increasing the thermal resistance of masonry wall systems is one effective ways to reduce energy consumption in operation buildings. This increase also demanded by newer, more stringent codes. However, ( R-value) walls affected many factors, such as bridging, which occurs places where highly conductive structural components penetrate insulating materials. Thermal bridging common when connecting...