Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi

• DOI: 10.48550/arxiv.2301.03800
• Publication Date: 2023-01-01
• Authors: Erjian Cheng; Limin Yan; Xianbiao Shi; Mahdi Behnami; Jian Yuan; Yuanji Xu; Yang Xu; Yimin Wan; Wei Xia; Nikolai Pavlovskii; Darren C. Peets; Weiwei Zhao; Yanfeng Guo; Shiyan Li; Wenge Yang; B. Büchner
• Keywords: Weyl semimetal; Magnetism

The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion (SI) and time-reversal (TR) symmetry breaking provides a unique platform for the exploration of novel topological states. Here, by employing electrical thermoelectrical transport, angle-resolved photoemission spectroscopy (ARPES), high-pressure techniques, band calculations, we demonstrate that magnetism pressure can serve as efficient parameters to tune positions nodes in CeAlSi. At ambient pressure, an anomalous Hall effect (AHE) Nernst (ANE) arise paramagnetic state, then are enhanced when temperature approaches ordering temperature, evidencing facilitates AHE/ANE. Such enhancement AHE/ANE be ascribed tuning via magnetism. ARPES measurements reveal ferromagnetism serves pivotal knob structure both bulk on surface. magnetism-tunable electronic has hitherto not been reported other magnetic $R$Al$Pn$ ($R$ = rare earth elements, $Pn$ Si, Ge) siblings, suggesting great potential controlling node Under sign change AHE discovered. Based evolution may root pressure. Moreover, multiple pressure-induced phase transitions uncovered. These findings indicate tunable exploring exotic physics electron correlations, well catering array applications, such spintronics thermoelectrics.