We present results on the low-frequency dynamical and transport properties of random quantum systems whose low temperature (T), low-energy behavior is controlled by strong-disorder fixed points. We obtain the momentumand frequency-dependent dynamic structure factor in the random singlet ~RS! phases of both spin-1/2 and spin-1 random antiferromagnetic chains, as well as in the random dimer and I...

A noninteracting quantum-dot arrays side coupled to a quantum wire is studied. Transport through the quantum wire is investigated by using a noninteracting Anderson tunneling Hamiltonian. The conductance at zero temperature develops an oscillating band with resonances and antiresonances due to constructive and destructive interference in the ballistic channel, respectively. Moreover, we have fo...

We consider the numerical solution on distributed-memory parallel arrays of vector processors of some large-scale eigenvalue problems which arise in chemistry and physics. Applications from a variety of areas are discussed, including molecular dynamics, quantum chemistry, optical physics, chemical reactions, and hydrodynamic stability.

We introduce two space-frequency adaptive strategies for the numerical approximation of the solutions of quantum hydrodynamic models for semiconductors, based respectively on wavelets and wavelet packets. The two strategies are compared on a test case, and wavelet packets perform better in approximating with fewer degrees of freedom the high frequency dispersive oscillations of the solution.

Asphaltene precipitation and deposition is a serious problem in many Iranian fields. The deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. This paper studies the asphaltene problem and mitigation methods in wellstring systematically. It presents new approach based on the combination of thermodynam...