Bi₄Br₄-based high-temperature quantum spin Hall physics

The manifestation of quantum phenomena at room temperatures is a major challenge but also a major goal in physics, and this is particularly true for the quantum spin Hall effect. Here we report the theoretical demonstration of a variety of high-temperature (and in some cases even room-temperature) quantum spin Hall systems based on Bi₄Br₄, a rare higher-order topological insulator identified recently. We also common on the key experimental studies.