Toward Topological Protection with Qubits

Reliable quantum computation will require devices that can protect fragile quantum states from environmental disturbances. To that end, some researchers have pinned their hopes on topological insulators, materials that intrinsically protect their novel electrical behavior in the face of external perturbations. However, no one has yet engineered a topological insulator in an ensemble of qubits, the quantum equivalent of digital bits. Now, Luyan Sun of Tsinghua University in Beijing and collaborators have done just that by crafting a string of qubits in which topological protection can be switched on and off at will.