Finite temperature properties of quarter-metals in rhombohedral multilayer graphene

Recent work by Young et al. demonstrates that at specific carrier densities and perpendicular displacement fields, rhombohedral multilayer graphene exhibits a spin- and valley-polarized ground state termed a quarter-metal [1]. Follow-up experiments [2] reveal non-trivial finite-temperature excitations in this phase, suggesting a state in which charge is nearly frozen while spin and valley degrees of freedom can fluctuate locally. Furthermore, this unique phase exhibits low resistance due to limited momentum relaxation channels. Motivated by these findings, we construct a simplified model using magnetic anisotropic energy parameters from constrained Hartree-Fock theory to examine the finite-temperature excitations of quarter-metals, estimating both the critical temperature and domain wall dimensions.

[1]:Haoxin Zhou et al.,Isospin magnetism and spin-polarized superconductivity in Bernal bilayer graphene.Science375,774-778(2022).DOI:10.1126/science.abm8386

[2] arXiv:2407.13763