# Physics Colloquium: Prof. Dr. Xiaodong Xu: Observation of Fractional Quantum Anomalous Hall Effect

### University of Washington, Department of Physics and Department of Materials Science and Engineering, Nanoscale Quantum Optoelectronics reasearch group, Seattle, WA, USA

The interplay between spontaneous symmetry breaking and topology can result in exotic quantum states of matter. A celebrated example is the quantum anomalous Hall (QAH) effect, which exhibits an integer quantum Hall effect at zero magnetic field due to topologically nontrivial bands and intrinsic magnetism. In the presence of strong electron-electron interactions, fractional-QAH (FQAH) effect at zero magnetic field can emerge, which is a lattice analog of fractional quantum Hall effect without Landau level formation.

In this talk, I will present experimental observation of FQAH effect in twisted MoTe_{2 }bilayer, using combined magneto-optical and -transport measurements. In addition, we find an anomalous Hall state near the filling factor -1/2, whose behavior resembles that of the composite Fermi liquid phase in the half-filled lowest Landau level of a two-dimensional electron gas at high magnetic field. Direct observation of the FQAH and associated effects paves the way for researching charge fractionalization and anyonic statistics at zero magnetic field.

### Time & Location

May 17, 2024 | 03:00 PM c.t.

Lecture Hall A (1.3.14)

Department of Physics

Arnimallee 14

14195 Berlin

### Further Information

### Host

### Keywords

- condensed matter theory
- electrical transport
- nanostructures
- optoelectronics
- physics
- quantum
- quantum physics
- research
- spectroscopy
- Xiaodong Xu