Abstract
Floquet–Bloch manipulation, achieved by driving a material periodically with a laser pulse, is a method that enables the engineering of electronic and magnetic phases in solids by effectively modifying the structure of their electronic bands. However, the application of Floquet–Bloch manipulation in topological magnetic systems, particularly those with inherent disorder, remains largely unexplored. Here we realize Floquet–Bloch manipulation of the Dirac surface-state mass of the topological antiferromagnet MnBi2Te4. Using time- and angle-resolved photoemission spectroscopy, we show that opposite helicities of mid-infrared circularly polarized light result in substantially different Dirac mass gaps in the antiferromagnetic phase, despite the equilibrium Dirac cone being massless. We explain our findings in terms of a Dirac fermion with a random mass. Our results underscore Floquet–Bloch manipulation as a powerful tool for controlling topology, even in the presence of disorder, and for uncovering properties of materials that may elude conventional probes.
| Original language | English |
|---|---|
| Pages (from-to) | 458-463 |
| Number of pages | 6 |
| Journal | Nature Physics |
| Volume | 21 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2025 |
Funding
We thank P. Abbamonte, P. Armitage, B. Bradlyn and K. Burch for insightful discussions. This work was supported by the Quantum Sensing and Quantum Materials, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences, under grant number DE-SC0021238. F.M. acknowledges support from the EPiQS programme of the Gordon and Betty Moore Foundation, grant number GBMF11069. N.B. acknowledges support from the Illinois Materials Research Science and Engineering Center, supported by the National Science Foundation MRSEC programme under NSF award number DMR-1720633. Y.D. acknowledges support from the Bloch Fellowship in quantum science and engineering from Stanford Q-FARM. Y.D., M.H., D.L. and Z.-X.S. acknowledge the support of the US Department of Energy, Office of Science, the Office of Basic Energy Sciences, Division of Material Sciences and Engineering, under grant number DE-AC02-76SF00515. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under grant number DE-AC02-76SF00515. Work at SIMES and ORNL was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. V.M. acknowledges support from the Gordon and Betty More Foundation EPiQS Initiative through grant number GBMF4860 and the Quantum Materials Program at CIFAR where she is a fellow. A.A. was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under grant number DE-SC0022101. C.F. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) under SFB1143 (project number 247310070), the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter—ct.qmat (EXC 2147, project number 390858490) and the QUAST-FOR5249-449872909.