From known phase diagram regions of different model Hamiltonians describing strongly correlated systems we deduced new domains of the ground state phase diagram of the same model by an unitary transformation. Different types of extended Hubbard Hamiltonians were used for the starting point and the existence of new stable spin-density wave, charge-density wave, ferromagnetic state and a paramagn...

In general, quantum systems are believed to be exponentially hard to simulate using classical computers. It is in these hard cases where we hope to find quantum algorithms that provide speed up over classical algorithms. In the paradigm of quantum adiabatic computation, instances of spin networks with 2-local interactions could hopefuly efficiently compute certain problems in NP-complete [4]. T...

in this paper, the hartree-fock method has been formulated to investigate some of the ground state properties of quasi-one-dimensional interacting electron gas in the presence of the magnetic field. the bare coulomb interaction between electrons has been assumed. for this system, we have also computed some of its thermodynamic and magnetic properties such as the energy, pressure, incompressibil...

Quantum tunneling of magnetization and quantum phase interference have been intensively studied in single molecule magnets (SMMs), high spin molecules with an easy axis (Ising) type magnetic anisotropy. SMMs have also been proposed as candidate qubits—and very recently several groups have reported the observation of coherent spin dynamics in pulsed EPR studies. In the first part of this talk I ...

We study a family of Hamiltonians of fermions hopping on a set of lattices in the presence of a background gauge field. The lattices are constructed by decorating the root lattices of various Lie algebras with their minuscule representations. The Hamiltonians are, in momentum space, themselves elements of the Lie algebras in these same representations. We describe various interesting aspects of...

We present a simple and pedagogical derivation of the spin current as the linear response to an external electric field for both Rashba and Luttinger spin–orbital coupling Hamiltonians. Except for the adiabatic approximation, our derivation is exact to the linear order of the electric field for both models. The spin current is a direct result of the difference in occupation levels between diffe...

We introduce and analyze a class of one-dimensional insulating Hamiltonians that, when adiabatically varied in an appropriate closed cycle, define a “Z2 pump.” For an isolated system, a single closed cycle of the pump changes the expectation value of the spin at each end even when spin-orbit interactions violate the conservation of spin. A second cycle, however, returns the system to its origin...

in this article, the second quantization method has been used to investigate some thermodynamic properties of spin-polarized metallic nanowire in the presence of magnetic field at zero temperature. we have been observed that in different magnetic field, the equilibrium energy of system increases as the density increases. the spin-polarization parameter corresponding to the equilibrium state of ...