# Quantum Anomalous Valley Hall Effect for Bosons

## TL;DR

This paper predicts a quantum anomalous valley Hall effect for bosonic excitons in 2D materials, showing quantized valley currents driven by light without magnetic fields, enabled by Bose-Einstein condensation.

## Contribution

It introduces the concept of quantum anomalous valley Hall effect for bosons and identifies key conditions for its realization in noncentrosymmetric 2D materials.

## Key findings

- Prediction of quantized valley Hall current for excitons
- Identification of conditions for QAVHE in 2D materials
- Demonstration of light-frequency-dependent quantized behavior

## Abstract

We predict the emergence and quantization of the valley Hall current of indirect excitons residing in noncentrosymmetric two-dimensional materials in the absence of an external magnetic field. Thus we report on the quantum anomalous valley Hall effect (QAVHE) for bosons. The crucial ingredients of its existence are the finite anomalous group velocity of exciton motion and the presence of the Bose-Einstein condensate, from which the particles are pushed out by external illumination to contribute to the stationary nonequilibrium current, which exhibits a quantized behavior as a function of the frequency of light.