arXiv subjects

Jiangping Hu

Publications and source records attributed to Jiangping Hu.

296 records · Page 17Linked to original sources

arXiv2005

Spin Polarization and Dichroism Effects by Electric Field

We show that electric field can induce spin polarization and dichroism effects in angle resolved photoemission spectroscopy (ARPES) in spin orbit coupling systems. The physical origin behind the effects essentially is the same as the spin Hall effect induced by the electric field. Since the ARPES experiments have both energy and momentum resolutions, the spin Hall effect can be directly verified by the ARPES experiments for individual band even if there is no net spin current.

cond-mat.mes-hall↗

arXiv2004

Fourier Transformed Scanning Tunneling Peaks in the $d$-density wave phase

In this brief note we repeat an earlier calculation of the Fourier transformed scanning tunneling spectra of the $d$-density wave (DDW) phase using a different band structure, which is more realistic and consistent with the angle resolved photoemission spectroscopy (ARPES) data. We note that four peaks, which used to be located at $(\pm π/4,0)$ and $(0, \pm π/4)$, are still present, but at positive energies their wavevectors shift to the neighborhood of $(\pm 2 π/5,0)$, $(0, \pm 2π/5)$ and slowly disperse with energy. The implications for the sensitivity with respect to the band structure are discussed.

cond-mat.supr-con↗

arXiv2003

Quasiparticle scattering and local density of states in the d-density wave phase

We study the effects of single-impurity scattering on the local density of states in the high-$T_c$ cuprates. We compare the quasiparticle interference patterns in three different ordered states: d-wave superconductor (DSC), d-density wave (DDW), and coexisting DSC and DDW (DSC-DDW). In the coexisting state, at energies below the DSC gap, the patterns are almost identical to those in the pure DSC state with the same DSC gap. However, they are significantly different for energies greater than or equal to the DSC gap. This transition at an energy around the DSC gap can be used to test the nature of the superconducting state of the underdoped cuprates by scanning tunneling microscopy. Furthermore, we note that in the DDW state the effect of the coherence factors is stronger than in the DSC state. The new features arising due to DDW ordering are discussed.

cond-mat.supr-con↗

arXiv2003

Spin Current in Spin-Orbit Coupling Systems

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 different bands. Moreover, we show a general topological spin current can be defined for a broad class of spin-orbit coupling systems.

cond-mat.mes-hall↗

arXiv2003

Comment on "Spontaneous breaking of time-reversal symmetry in the pseudogap state of a high-T$_c$ superconductor"

We argue that that in their recent experiment in which they claim to have found evidence for a time-reversal symmetry broken state, Kaminski et al. overlooked small temperature dependent changes in the superstructure of Bi2212. These subtle changes may manifest themselves by changing the final state configurations of the photoemission process and thus invalidate their ultimate conclusions.

cond-mat.supr-con↗

arXiv2001

Collective excitations at the boundary of a 4D quantum Hall droplet

In this work we investigate collective excitations at the boundary of a recently constructed 4D quantum Hall state. Local bosonic operators for creating these collective excitations can be constructed explicitly. Massless relativistic wave equations with helicity $S$ can be derived exactly for these operators from their Heisenberg equation of motion. For the S=1 and S=2 cases these equations reduce to the free Maxwell and linearized Einstein equation respectively. These collective excitations can be interpreted as hydrodynamical modes at the boundary of the 4D QHE droplet. Outstanding issues are critically discussed.

cond-mat.mes-hall↗

arXiv2001

A Four Dimensional Generalization of the Quantum Hall Effect

We construct a generalization of the quantum Hall effect, where particles move in four dimensional space under a SU(2) gauge field. This system has a macroscopic number of degenerate single particle states. At appropriate integer or fractional filling fractions the system forms an incompressible quantum liquid. Gapped elementary excitations in the bulk interior and gapless elementary excitations at the boundary are investigated.

cond-mat↗

arXiv2001

Dispersoin of the πresonance

We study the dispersion of the $π$ resonance in the superconducting state within the projected SO(5) model\cite{project}. Away from the the commensurate momentum, the propagation of the $π$ resonance creates phase slips in the superconducting order parameter. This frustration effect leads to a strong dressing of the $π$ resonance and a downwards dispersion away from the commensurate wave vector. Based on these results, we argue that the the commensurate resonance and incommensurate magnetic fluctuations in the cuprates are continuously connected.

cond-mat.supr-con↗