相关论文: Magnetic-field Induced Screening Effect and Collec…
We report on our theoretical investigations that point to the possibility of a fractional quantum Hall effect with partial spin polarization at $\nu=3/8$. The physics of the incompressible state proposed here involves p-wave pairing of…
A coordinate-space representation for a charged scalar particle propagator in a constant magnetic field was obtained as a series over the Landau levels. Using the recently developed modified Fock-Schwinger method, an intermediate expression…
Two-dimensional electrons in graphene are known to behave as massless fermions with Dirac-Weyl type linear dispersion near the Dirac crossing points. We have investigated the collective excitations of this system in the presence or absence…
Characteristic properties of magnetic field effects on spin selective geminate and bulk electron-hole polaron pair (PP) recombination are analyzed in detail within the approach based on the stochastic Liouville equation. Simple expressions…
The activation gap $\Delta$ of the fractional quantum Hall states at constant fillings $\nu =2/3$ and 2/5 has been measured as a function of the perpendicular magnetic field $B$. A linear dependence of $\Delta$ on $B$ is observed while…
We investigate collective spin excitations of graphene electrons with short-ranged interactions and subject to the external Zeeman magnetic field. We find that in addition to the familiar Silin spin wave, a collective spin-flip excitation…
We study fermions in a magnetic field in a finite size cylinder. With the boundary condition for the fermion flux, we show that the energy spectra and the wave-functions are modified by the finite size effect; the boundary makes the…
We present a Random-Phase-Approximation formalism for the collective spectrum of two hyperfine species of dilute 40K atoms, magnetically trapped at zero temperature and subjected to a repulsive s-wave interaction between atoms with…
We study collective electronic excitations in graphene in the integer quantum Hall regime, concentrating mainly on excitations with spin reversal such as spin-flip and spin-wave excitations. We show that these excitations are correctly…
We extend a microscopic theory of polarization and magnetization to include the spin degree of freedom of the electrons, introducing a general spin orbit coupling and Zeeman interaction term in the Hamiltonian. At finite frequencies and…
We consider the effects of a noisy magnetic field background over the fermion propagator in QED, as an approximation to the spatial inhomogeneities and time-fluctuations that would naturally arise in certain physical scenarios, such as…
We consider a novel contribution to the polarization of the Cosmic Microwave Background induced by vector and tensor modes generated by the non-linear evolution of primordial scalar perturbations. Our calculation is based on relativistic…
The edge of spin unpolarized or spin polarized $\nu=2/3$ fractional quantum Hall states is predicted by the effective theory to support a backward moving neutral mode in addition to a forward moving charge mode. We study this issue from a…
We compute the photon polarization tensor at one-loop order in the presence of a constant and uniform electric field. Our calculation is carried out for arbitrary field strength using the Schwinger proper-time formalism, and we explicitly…
We show that a large contribution to tensor modes during inflation can be generated by a spectator scalar field with speed of sound lower than unity.
The recent progress on the study of the collective excitation in relativistic nuclear matter is reviewed. The collective excitation modes are derived by meson propagators in nuclear matter. The mesons we study are $\sigma, \omega, \gamma$…
We formulate the coupling between fermion spin and background electromagnetic fields using form factors. We show that the vacuum form factors at tree level reproduce the spin polarization effects found in chiral kinetic theory. The vacuum…
The equilibrium magnetization for layered superconducting films that experience a nonzero component, $H_{\parallel}$, of magnetic field applied parallel to the layers is computed at temperatures and at perpendicular field components in the…
We report on an effective vector-field theory of the fractional quantum Hall effect that takes into account projection to Landau levels. The effective theory refers to neither the composite-boson nor composite-fermion picture, but properly…
A magnetic field induced electric polarization and the corresponding change of an effective junction capacitance are considered within a 3D model of disordered Josephson junction arrays. At some threshold field (near the Josephson network…