arXiv subjects

An Du

Publications and source records attributed to An Du.

6 recordsLinked to original sources

arXiv2025

Quantum control and the topological properties of the magnon photo-transport in two-dimensional collinear ferromagnet

In this work, we investigate light-induced magnon spin photocurrent (MSPC) and magnon energy photocurrent (MEPC) via the Aharonov-Casher (AC) effect. We treat the influence of the electric field through the AC effect as a perturbative term. Subsequently, we derived explicit expressions for MSPC and MEPC in a two-dimensional, collinear ferromagnetic system. Our theoretical framework is applied to both Hexagonal and Kagome two-dimensional ferromagnetic lattices. We demonstrate that MSPC and MEPC can be modulated by tuning the optical frequency and the material's relaxation time. Furthermore, in the low-frequency and infinite-relaxation-time limit, longitudinal MS(E)PC correlates with the topological properties of the magnon system.

cond-mat.mes-hall↗

arXiv2016

Influence of $\mathcal{PT}$-symmetric complex potentials on the decoupling mechanism in quantum transport process

We consider one system in which the terminal dots of a one-dimensional quantum-dot chain couple equally to the left and right leads and study the influence of $\mathcal{PT}$-symmetric complex potentials on the quantum transport process. It is found that in the case of the Hermitian Hamiltonian, remarkable decoupling and antiresonance phenomena have an opportunity to co-occur in the transport process. For the chains with odd(even) dots, all their even(odd)-numbered molecular states decouple from the leads. Meanwhile, antiresonance occurs at the positions of the even(odd)-numbered eigenenergies of the sub-chains without terminal dots. When the $\mathcal{PT}$-symmetric complex potentials are introduced to the terminal dots, the decoupling phenomenon is found to transform into the Fano antiresonance. In addition, it shows that appropriate magnetic flux can interchange the roles of the odd and even molecular states. These results can assist to understand the quantum transport modified by the $\mathcal{PT}$ symmetry in non-Hermitian discrete systems.

quant-ph↗

arXiv2016

Evidence of the stability of Mo_{2}TiAlC_{2} from first principles calculations and its thermodynamical and optical properties

The elastic, thermodynamic, and optical properties of Mo_{2}TiAlC_{2} are investigated by first-principles calculations. Our results indicate that the a axis is stiffer than c axis within 0~100 GPa. Elastic constants calculations predict the large stability range of Mo_{2}TiAlC_{2} under pressure. Several important thermodynamic properties are discussed detailedly, including the Debye temperature, thermal expansion coefficient, and heat capacity etc. The bonding properties are studied from the elastic quantities and electronic properties. The electronic properties are investigated, including the energy band structure, density of states, and so on. The evidence of the instability of Mo_{3}AlC_{2} and stability of Mo_{2}TiAlC_{2} are successfully obtained.

cond-mat.mes-hall↗

arXiv2015

Rigorous determination of the ground-state phases and thermodynamics in an Ising-type multiferroic Ca3CoMnO6 chain

To understand the collinear-magnetism-driven ferroelectricity in multiferroic Ca3CoMnO6 compound, we have established an elastic diatomic Ising spin-chain model with axial-next-nearest-neighbor interaction to describe its magnetoelectric properties. By employing magneto-phonon decoupling and transfer-matrix method, the possible ground-state configurations and thermodynamic behaviors of the system have been exactly determined. From the perspective of the ground-state configuration, we analyze the computational results and make a detail comparison with experimental data. The parameter relation for the appearance of electric polarization has been discussed. Our data indicate that the magnetic coupling between nearest-neighbor spin pair is antiferromagnetic rather than ferromagnetic. The system under the driven of external magnetic field undergoes a different series of transitions from the up-up-down-down spin configuration to the up-down-up state with peculiar 1/3 magnetization plateau, then to the up-up-up-down state, and finally saturated at up-up-up-up state.

cond-mat.stat-mech↗

arXiv2014

Magnetic field control of ferroelectric polarization and magnetization of LiCu2O2 compound

A spin model of LiCu2O2 compound with ground state of ellipsoidal helical structure has been adopted. Taking into account the interchain coupling and exchange anisotropy, we focus on the magnetoelectric properties in a rotating magnetic field and perform the Monte Carlo simulation on a two-dimensional lattice. A prominent anisotropic response is observed in the magnetization and polarization curves, qualitatively coinciding with the behaviors that detected in the experiment. In addition, the influences of the magnetic field with various magnitudes are also explored and analyzed in detail. As the magnetic field increases, a much smoother polarization of angle dependence is exhibited, indicating the strong correlation between the magnetic and ferroelectric orders.

cond-mat.mtrl-sci↗

arXiv2013

Thermodynamic properties of LiCu$_{2}$O$_{2}$ multiferroic compound

A spin model of quasi-one dimensional LiCu$_{2}$O$_{2}$ compound with ground state of ellipsoidal helical structure in which the helical axis is along the diagonal of CuO$_{4}$ squares has been adopted. By taking into account the interchain coupling and exchange anisotropy, the exotic magnetic properties and ferroelectricity induced by spiral spin order have been studied by performing Monte Carlo simulation. The simulation results qualitatively reproduce the main characters of ferroelectric and magnetic behaviors of LiCu$_{2}$O$_{2}$ compound and confirm the low-temperature incollinear spiral ordering. Furthermore, by performing the calculations of spin structure factor, we systematically investigate the effects of different exchange coupling on the lower-temperature magnetic transition, and find that the spiral spin order depends not only on the ratio of nearest and next-nearest neighbor inchain spin coupling but also strongly on the exchange anisotropy.

cond-mat.mtrl-sci↗