Insulator to Metal Transition, Spin-Phonon Coupling, and Potential Magnetic Transition Observed in Quantum Spin Liquid Candidate LiYbSe$_2$ under High Pressure

Haozhe Wang; Lifen Shi; Shuyuan Huyan; Greeshma C. Jose; Barbara Lavina; Sergey L. Bud'ko; Wenli Bi; Paul C. Canfield; Jinguang Cheng; Weiwei Xie

arXiv · 2312.00270

Insulator to Metal Transition, Spin-Phonon Coupling, and Potential Magnetic Transition Observed in Quantum Spin Liquid Candidate LiYbSe$_2$ under High Pressure

Haozhe Wang·Lifen Shi·Shuyuan Huyan·Greeshma C. Jose·Barbara Lavina·Sergey L. Bud'ko·Wenli Bi·Paul C. Canfield·Jinguang Cheng·Weiwei Xie

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Abstract

Metallization of quantum spin liquid (QSL) materials has long been considered as a potential route to achieve unconventional superconductivity. Here we report our endeavor in this direction by pressurizing a three-dimensional QSL candidate, LiYbSe$_2$, with a previously unreported pyrochlore structure. High-pressure X-ray diffraction and Raman studies up to 50 GPa reveal no appreciable changes of structural symmetry or distortion in this pressure range. This compound is so insulating that its resistance decreases below 10$^5$ ${\Omega}$ only at pressures above 25 GPa in the corresponding temperature range accompanying the gradual reduction of band gap upon compression. Interestingly, an insulator-to-metal transition takes place in LiYbSe$_2$ at about 68 GPa and the metallic behavior remains up to 123.5 GPa, the highest pressure reached in the present study. A possible sign of magnetic or other phase transition was observed in LiYbSe$_2$. The insulator-to-metal transition in LiYbSe$_2$ under high pressure makes it an ideal system to study the pressure effects on QSL candidates of spin-1/2 Yb$^{3+}$ system in different lattice patterns.

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Haozhe Wang, Lifen Shi, Shuyuan Huyan, Greeshma C. Jose, Barbara Lavina, Sergey L. Bud'ko, Wenli Bi, Paul C. Canfield, Jinguang Cheng, Weiwei Xie. 2023-12-01. Insulator to Metal Transition, Spin-Phonon Coupling, and Potential Magnetic Transition Observed in Quantum Spin Liquid Candidate LiYbSe$_2$ under High Pressure. https://arxiv.org/abs/2312.00270

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