Fermi surface study of the putative spin-triplet superconductor UTe<sub>2</sub>
ORAL
Abstract
The unconventional superconductor UTe2 exhibits numerous properties indicative of spin-triplet pairing, including an upper critical field far in excess of the Pauli paramagnetic limit, and re-entrant superconductivity at high magnetic fields > 40 T. However, a detailed understanding of the material's Fermi surface remains a key open question hampering efforts to attain a more detailed theoretical picture of the microscopic pairing mechanism(s) at play.
Here, we report a detailed de Haas-van Alphen study of the Fermi surface of UTe2. We measured quantum oscillations in the magnetic torque and contactless resistivity of several high quality samples (RRR ~ 900, Tc = 2.1 K) in a dilution refrigerator at temperatures down to 19 mK and magnetic fields up to 28 T, through two orthogonal rotation planes. Importantly, access to field strengths this high allowed us to measure directly along the [001] direction, which has previously been proposed to run parallel to the axis of cylindrical Fermi surface sections.
We present a summary of our angle- and temperature-dependent results performed to date, and compare to DFT and DMFT calculations that we find to capture the majority of the observed behavior.
Here, we report a detailed de Haas-van Alphen study of the Fermi surface of UTe2. We measured quantum oscillations in the magnetic torque and contactless resistivity of several high quality samples (RRR ~ 900, Tc = 2.1 K) in a dilution refrigerator at temperatures down to 19 mK and magnetic fields up to 28 T, through two orthogonal rotation planes. Importantly, access to field strengths this high allowed us to measure directly along the [001] direction, which has previously been proposed to run parallel to the axis of cylindrical Fermi surface sections.
We present a summary of our angle- and temperature-dependent results performed to date, and compare to DFT and DMFT calculations that we find to capture the majority of the observed behavior.
*A. G. Eaton acknowledges support from a QuantEmX grant from ICAM and the Gordon and Betty Moore Foundation through Grant GBMF5305; from the Henry Royce Institute for advanced materials through the Equipment Access Scheme enabling access to XPS Suite and Ambient Cluster Tool facilities at Cambridge, EPSRC Grant Number EP/R00661X/1; and from Sidney Sussex College (University of Cambridge). A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1644779* and the State of Florida.
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Presenters
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Alexander G Eaton
- University of Cambridge