Thermal Hall conductivity of electron-doped cuprates

Journal Article · 01 March 2022 · Physical Review. B

DOI: https://doi.org/10.1103/physrevb.105.115101 · OSTI ID:1867007

Boulanger, Marie-Eve  ^[1]; Grissonnanche, Gaël  ^[1]; Lefrançois, Étienne  ^[1]; Gourgout, Adrien ^[1]; Xu, Ke-Jun ^[2]; Shen, Zhi-Xun ^[2]; Greene, Richard L.  ^[3]; Taillefer, Louis  ^[4]

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1. Univ. de Sherbrooke, Quebec (Canada)
2. Stanford Univ., CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
3. Univ. of Maryland, College Park, MD (United States)
4. Univ. de Sherbrooke, Quebec (Canada); Canadian Inst. for Advanced Research, Ontario (Canada)

Measurements of the thermal Hall conductivity in hole-doped cuprates have shown that phonons acquire chirality in a magnetic field both in the pseudogap phase and in the Mott insulator state. The microscopic mechanism at play is still unclear. A number of theoretical proposals are being considered including skew scattering of phonons by various defects, the coupling of phonons to spins, and a state of loop-current order with the appropriate symmetries, but more experimental information is required to constrain theoretical scenarios. Here we present our study of the thermal Hall conductivity κ_xy in the electron-doped cuprates Nd_2–xCe_xCuO₄ and Pr_2–xCe_xCuO₄ for dopings across the phase diagram, from x = 0 in the insulating antiferromagnetic phase up to x = 0.17 in the metallic phase above optimal doping. We observe a large negative thermal Hall conductivity at all dopings in both materials. Since heat conduction perpendicular to the CuO₂ planes is dominated by phonons, the large thermal Hall conductivity we observe in electron-doped cuprates for a heat current in that direction must also be due to phonons, as in hole-doped cuprates. However, the degree of chirality, measured as the ratio |κ_xy/κ_xx| where κ_xx is the longitudinal thermal conductivity, is much larger in the electron-doped cuprates. Here, we discuss various factors that may be involved in the mechanism that confers chirality to phonons in cuprates, including short-range spin correlations.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; National Science Foundation
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1867007
• Journal Information: Physical Review. B, Journal Name: Physical Review. B Journal Issue: 11 Vol. 105; ISSN 2469-9950
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English