Spin Splitting Nernst Effect in Altermagnet

Abstract

Altermagnet is a distinctive magnet phase, which has spin-split energy band but with zero net magnetic moment. In this paper, we propose that altermagnet behaves spin splitting Nernst effect: Under a longitudinal temperature gradient, the electrons with opposite spins tend to split oppositely in the transverse direction, thus generating a transverse spin current. The spin splitting Nernst effect is understood from the contribution of the longitudinal wave vector to the transverse group velocity. Using the nonequilibrium Green's function method, we calculate the spin-dependent transmission coefficient in the four-terminal altermagnet device. From the spin-dependent transmission coefficient, the nonzero transverse spin current from longitudinal temperature gradient is obtained, and the spin splitting Nernst effect is verified. We systematically study the parameter dependence of the spin splitting Nernst effect, while also performing symmetry analysis. The spin splitting Nernst effect can be easily regulated by Fermi surface energy, temperature, transport direction, and system size. Furthermore, in altermagnet, the $xy$-response and $yx$-response spin splitting Nernst coefficients are equal with $N_{s,xy}=N_{s,yx}$, different from the conventional spin Nernst effect where they are opposite. Meanwhile, the spin splitting Nernst effect require neither spin-orbit coupling nor net magnetism.

References in corpus (8)

• Bulk Topological Invariants in Noninteracting Point Group Symmetric Insulators
• Spin Nernst effect and Nernst effect in two-dimensional electron systems
• Orientation-dependent Josephson effect in spin-singlet superconductor/altermagnet/spin-triplet superconductor junctions
• Field-free Josephson diode effect in altermagnet/normal metal/altermagnet junctions
• Tunable large spin Hall and spin Nernst effects in Dirac semimetals ZrXY (X=Si, Ge; Y=S, Se, Te)
• Spin-dependent thermoelectric transport in HgTe/CdTe quantum wells
• Charge and spin transport through normal lead coupled to $s$-wave superconductor and a Majorana zero mode
• Spin-triplet superconductor$-$quantum anomalous Hall insulator$-$spin-triplet superconductor Josephson junctions: $0$-$\pi$ transition, ${\varphi }_0$ phase and switch effects

Cited by in corpus (9)

• Tunneling Magnetoresistance Effect in Altermagnets
• Interplay of Altermagnetic Order and Wilson Mass in the Dirac Equation: Helical Edge States without Time-Reversal Symmetry
• Helical Fermi Arc in Altermagnetic Weyl Semimetal
• The emergence of net chirality in two-dimensional Dirac fermions system with altermagnetic mass
• Tunable two-dimensional Dirac-Weyl semimetal phase induced by altermagnetism
• Majorana modes in helical altermagnet without net magnetism and spin-orbit coupling
• Quantum anomalous Hall effect with tunable Chern numbers induced by d-wave sublattice-staggered altermagnetism
• Unconventional Spin Valve Based on Normal Metal/Chiral Molecule/Altermagnet Junctions
• Spin transport in a normal meta-altermagnetic superconducting nanowire junction