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DOE OSTI · 3021956

Field Induced Density Wave in a Kagome Superconductor

Hossain, Md. Shafayat [University of California, Los Angeles, CA (United States); Princeton University, NJ (United States)] (ORCID:0000000237445877)·Zhang, Qi [Princeton University, NJ (United States)]·Ingham, Julian [Columbia University, New York, NY (United States)] (ORCID:0000000277339833)·Liu, Jinjin [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)]·Shao, Sen [Nanyang Technological University (Singapore)]·Li, Yangmu [Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000308862919)·Wang, Yuxin [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000280168238)·Pokharel, Bal K. [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000205706796)·Cheng, Zi-Jia [Princeton University, NJ (United States)]·Jiang, Yu-Xiao [Princeton University, NJ (United States)] (ORCID:0000000279583100)·Litskevich, Maksim [Princeton University, NJ (United States)]·Kim, Byunghoon [Princeton University, NJ (United States)] (ORCID:0000000189494833)·Yang, Xian [Princeton University, NJ (United States)]·Li, Yongkai [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)]·Cochran, Tyler A. [Princeton University, NJ (United States)]·Yao, Yugui [Beijing Institute of Technology (China)]·Popović, Dragana [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000225713627)·Wang, Zhiwei [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)]·Thomale, Ronny [University of Würzburg (Germany)]·Balicas, Luis [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000252090293)·Hasan, M. Zahid [Princeton University, NJ (United States)]
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Abstract

On the kagome lattice, electrons benefit from the simultaneous presence of band topology, flat electronic bands, and Van Hove singularities, forming competing or cooperating orders. Understanding the interrelation between these distinct order parameters remains a significant challenge, leaving much of the associated physics unexplored. In the kagome superconductor KV 3 Sb 5 , which exhibits a charge density wave (CDW) state below T ≃ 78 K, we uncover an unpredicted field-induced phase transition below 6 K. The observed transition is marked by a hysteretic anomaly in the resistivity, nonlinear electrical transport, and a change in the symmetry of the electronic response as probed via the angular dependence of the magnetoresistivity. These observations surprisingly suggest the emergence of an unanticipated broken symmetry state coexisting with the original CDW. To understand this experimental observation, we developed a theoretical minimal model for the normal state inside the high-temperature parent CDW phase, where an incommensurate CDW order emerges as an instability subleading to superconductivity. Here, the incommensurate CDW emerges when superconducting fluctuations become fully suppressed by large magnetic fields. Our results suggest that, in kagome superconductors, quantum states can either coexist or are nearly degenerate in energy, indicating that these are rich platforms to expose new correlated phenomena.

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Hossain, Md. Shafayat [University of California, Los Angeles, CA (United States); Princeton University, NJ (United States)] (ORCID:0000000237445877), Zhang, Qi [Princeton University, NJ (United States)], Ingham, Julian [Columbia University, New York, NY (United States)] (ORCID:0000000277339833), Liu, Jinjin [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)], Shao, Sen [Nanyang Technological University (Singapore)], Li, Yangmu [Chinese Academy of Sciences, Beijing (China)] (ORCID:0000000308862919), Wang, Yuxin [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000280168238), Pokharel, Bal K. [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000205706796), Cheng, Zi-Jia [Princeton University, NJ (United States)], Jiang, Yu-Xiao [Princeton University, NJ (United States)] (ORCID:0000000279583100), Litskevich, Maksim [Princeton University, NJ (United States)], Kim, Byunghoon [Princeton University, NJ (United States)] (ORCID:0000000189494833), Yang, Xian [Princeton University, NJ (United States)], Li, Yongkai [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)], Cochran, Tyler A. [Princeton University, NJ (United States)], Yao, Yugui [Beijing Institute of Technology (China)], Popović, Dragana [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000225713627), Wang, Zhiwei [Beijing Institute of Technology (China); Beijing Institute of Technology, Zhuhai (China)], Thomale, Ronny [University of Würzburg (Germany)], Balicas, Luis [National High Magnetic Field Laboratory, Tallahassee, FL (United States)] (ORCID:0000000252090293), Hasan, M. Zahid [Princeton University, NJ (United States)]. 2025-10-29. Field Induced Density Wave in a Kagome Superconductor. https://doi.org/10.1103/5f9f-bsqw

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