arXiv subjects

L. F. Zhang

Publications and source records attributed to L. F. Zhang.

4 recordsLinked to original sources

arXiv2023

Nonlinear phonon Hall effects in ferroelectrics: its existence and non-volatile electrical control

Nonlinear Hall effects have been previously investigated in non-centrosymmetric systems for electronic systems. However, they only exist in metallic systems and are not compatible with ferroelectrics since these latter are insulators, hence limiting their applications. On the other hand, ferroelectrics naturally break inversion symmetry and can induce a non-zero Berry curvature. Here, we show that a non-volatile electric-field control of heat current can be realized in ferroelectrics through the nonlinear phonon Hall effects. More precisely, based on Boltzmann equation under the relaxation-time approximation, we derive the equation for nonlinear phonon Hall effects, and further show that the behaviors of nonlinear phonon (Boson) Hall effects are very different from nonlinear Hall effects for electrons (Fermion). Our work provides a route for electric-field control of thermal Hall current in ferroelectrics.

cond-mat.mtrl-sci↗

arXiv2017

The limits of the nuclear landscape explored by the relativistic continuum Hatree-Bogoliubov theory

The ground-state properties of nuclei with 8 $\le$ Z $\le$ 120 from the proton drip line to the neutron drip line have been investigated using the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the relativistic density functional PC-PK1. With the effects of the continuum included, there are totally 9035 nuclei predicted to be bound, which largely extends the existing nuclear landscapes predicted with other methods. The calculated binding energies, separation energies, neutron and proton Fermi surfaces, root-mean-square (rms) radii of neutron, proton, matter, and charge distributions, ground-state spins and parities are tabulated. The extension of the nuclear landscape obtained with RCHB is discussed in detail, in particular for the neutron-rich side, in comparison with the relativistic mean field calculations without pairing correlations and also other predicted landscapes. It is found that the coupling between the bound states and the continuum due to the pairing correlations plays an essential role in extending the nuclear landscape. The systematics of the separation energies, radii, densities, potentials and pairing energies of the RCHB calculations are also discussed. In addition, the alpha-decay energies and proton emitters based on the RCHB calculations are investigated.

nucl-th↗

arXiv2008

Magnetophoresis of nonmagnetic particles in ferrofluids

Ferrofluids containing nonmagnetic particles are called inverse ferrofluids. On the basis of the Ewald-Kornfeld formulation and the Maxwell-Garnett theory, we theoretically investigate the magnetophoretic force exerting on the nonmagnetic particles in inverse ferrofluids due to the presence of a nonuniform magnetic field, by taking into account the structural transition and long-range interaction. We numerically demonstrate that the force can be adjusted by choosing appropriate lattices, volume fractions, geometric shapes, and conductivities of the nonmagnetic particles, as well as frequencies of external magnetic fields.

physics.chem-ph↗

arXiv2006

Magnetophoresis of ferrofluid in microchannel system and its nonlinear effect

We have studied the magnetophoretic particle separation and its nonlinear behavior of ferrofluids in microchannel which is proposed by Furlani. The magnetic gradient force is caused by an bias field and the polarized magnets and is found to be spatially uniform in the channel section which can be used for particle selecting or separation. We have derived the equations of nonlinear magnetization of magnetic particles which cause the harmonics of magnetophoresis. The Langevin model and generalized Clausius-Mossotti equation used show how the normal and longitude anomalous anisotropic effect the permeability of ferrofluids, thus the magnetic force. Our analysis demonstrates the viability of using the microchannel system for various bioapplications and other characterization of fluid transporting and the time-varying magnetic field can be potentially used for an integrated magnetometer and influences the the viscosity and effective permeability in ferrofluids.

physics.bio-ph↗