2026/11/17(Tue) 10:30 -11:50 五樓第一會議室 5F, 1st Meeting Room
Title
Pressure Quenching: A Path to Record 151 K Superconductivity at Ambient Pressure
Speaker
Asst. Prof. Liangzi Deng (Department of Physics, University of Houston)Abstract
Diamond forms deep within the Earth yet can persist at its surface for billions of years – a natural reminder that a phase created under pressure need not vanish when that pressure is released. Pressure is one of the cleanest knobs for tuning quantum materials: it can raise superconducting transition temperatures (Tc) well above their ambient values and, as our recent work shows, drive superconductivity beyond conventional Tc–pressure relationships and substantially widen the temperature–magnetic-field window that hosts skyrmions. Yet these states typically disappear on decompression, and the confines of the diamond anvil cell limit how they can be probed and used. Can we keep what pressure creates? To answer this question, we developed the pressure-quench protocol (PQP), a nonequilibrium approach that kinetically traps pressure-induced or pressure-enhanced quantum states at ambient pressure by tuning the quench pressure, temperature, and rate. In this talk, I will trace PQP from FeSe—whose superconductivity was discovered right here at Academia Sinica—and the topological insulator Bi0.5Sb1.5Te3 to the cuprate HgBa2Ca2Cu3O8+δ (Hg1223) [1–3], where pressure quenching raises the ambient-pressure Tc to 151 K, surpassing a record that had stood since 1993. Synchrotron X-ray diffraction and transmission electron microscopy show that quenched Hg1223 retains its tetragonal structure while carrying quench-induced defects appear to stabilize the metastable state. Drawing on pressure quenching results across these systems, I will discuss how electronic transitions, lattice evolution, defects, and kinetic barriers act along the pressure–temperature pathway to determine which states survive, as a step toward predictive design principles for metastable quantum matter. PQP opens a path beyond the three-decade plateau in ambient-pressure Tc and provides a general platform for bringing quantum states once confined to extreme pressures into the ambient-pressure laboratory, making them accessible to a full suite of experimental probes and, ultimately, practical applications.
References
1.L. Z. Deng et al. Ambient-pressure 151-K superconductivity in HgBa2Ca2Cu3O8+δ via pressure quench. Proc. Natl. Acad. Sci. U.S.A. 123, e2536178123 (2026).
2.L. Z. Deng et al. Creation, stabilization, and investigation at ambient pressure of pressure-induced superconductivity in Bi0.5Sb1.5Te3. Proc. Natl. Acad. Sci. U.S.A. 122, e2423102122 (2025).
3.L. Z. Deng et al. Pressure-induced high-temperature superconductivity retained without pressure in FeSe single crystals. Proc. Natl. Acad. Sci. U.S.A. 118, e2108938118 (2021).
Language
演講語言 (Language): in English
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