A Room-Temperature Quantum Computing Architecture via a Novel 2D Quantum Material

Topological insulators (TI) are an emerging quantum material family which has topologically-protected metallic states from which the material is characterized as either two-dimensional (2D) or three-dimensional (3D). In both forms, the material has an insulating interior but the 2D form has edge states while the 3D form has surface states. Curiously, the 2D TI edge states are resistant to electron back-scattering due to topological protection allowing for dissipation less transport. Transport in these 2D systems are akin to the quantum spin hall insulator which allows counter-propagating spin-polarized currents. However, just like in the quantum spin hall model, a symmetry-breaking magnetic field will break the degenerate energy levels of the currents forcing either a clockwise or counter-clockwise current to remain. This inherent two-state system forms the basis for our qubit architecture.

Our lab synthesizes TIs from the chalcogenide family (Bi₂Te₃, Sb₂Te₃, Bi₂Se₃) and specialize in manipulating the synthesis to produce nanorods, hexagonal nanoplates, nanoplates with nanopores, and spiral-type nanoplates. The spiral-type nanoplates is the geometry of interest for our quantum computing architecture and are colloquially called SQUIRLs.

The SQUIRLS structure origins from a screw-dislocation during synthesis causing the nanoplate to form a continuous layer spiraling upwards. The spiral-type nanoplates grow on both sides of the screw-dislocation allowing mirror spiral structures separated by a habit plane. Electron transport measurements on SQUIRLS indicate metallic edge states within the bandgap at room-temperature. Due to the degenerate edge spin currents the SQUIRLS have a two-state personality analogous to the SQUID architectures. Estimations show the dephasing time of these topologically protected states to be sub-micro second, however we believe the ability to operate these systems at room-temperatures may allow for specific applications in the quantum computing field.

In this presentation we will demonstrate current advancements within our lab on the circuit design, qubit readout, T-gate implementation, electro-magnetic simulations and future directions.