As a large number of qubits will be integrated on a chip to enable algorithms for classically intractable problems, the phase decoherence and quantum-classical interface pose severe challenges in how to scale up a quantum computer. This task increasingly requires a nexus between continued fundamental advances in physics, materials, engineering design, and prototype development. In this talk, I will show recent progress in developing topological insulator-based microstructures that may meet the requirements imposed on the control and readout of quantum computing hardware.
First, I will describe the fabrication and measurements of a superconductor/topological insulator heterostructure. This heterostructure supports phase-slip lines that act as effective Josephson junctions. By probing the response of the system to microwave radiation, we find that the Shapiro response exhibits a missing first Shapiro step and an unexpectedly wide second Shapiro step.
Second, I will show the development of topological circulators using the quantum anomalous Hall insulators. We reveal the dispersion relation of edge magnetoplasmons in quantum anomalous Hall insulator using microwave measurements. By systematically varying the circulator radius, we found the plasmon dispersion is highly nonlinear and exhibits the intrinsic decay time on the order of nanosecond.
Finally, I will discuss our plan to integrate topological circulators with qubits and a multicavity Axion haloscope.