2025/10/15 by Zhao, Jing-Yu, Chatterjee, Shubhayu, Sachdev, Subir +1 · 2 citations
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2510.13943
Recent angle-dependent magnetoresistance measurements in underdoped cuprates have revealed compelling evidence for small hole pockets in the pseudogap regime, including observation of the Yamaji effect in HgBa2CuO4+δ (Chan et al., Nature Physics 10.1038/s41567-025-03032-2 (2025)). A key distinction between theories is their predicted Fermi volumes, measured as fractions of the square lattice Brillouin zone: p/4 per pocket for spin density wave (SDW) versus p/8 for fractionalized Fermi liquid (FL*), where p is the hole doping. We calculate the c-axis magnetoresistance ρzz(θ, ϕ) within the semiclassical Boltzmann formalism for both states, and using the ancilla layer model (ALM) for FL* in a single-band Hamiltonian. The results from the FL^* phase show good consistency with current experimental data. Conversely, the results for the SDW phase are highly sensitive to the ordering momentum along the z-direction. An ordering vector of Q = (π, π, π) yields predictions that starkly disagree with the experiment. The only possibility for agreement within the SDW scenario is to assume an ordering momentum of Q = (π, π, 0). However, even in this specific case, the SDW scenario predicts a marginally smaller Yamaji angle at ϕ=0 than the FL* theory, and a second Yamaji peak near in-plane angle ϕ= 45^∘, which was not observed in the experiment. In reality, the Néel ordering vector is likely uncorrelated between adjacent layers, so that there is no coherent interlayer transport of hole-pocket quasiparticles in the SDW scenario, and consequently no Yamaji effect. Our results support the FL* interpretation of Fermi arcs in the pseudogap phase, and establish Yamaji angle measurements as a discriminatory tool between theoretical models.