Determining quantum phase diagrams of topological Kitaev-inspired models on NISQ quantum hardware

Quantum 5, 553 (2021).

https://doi.org/10.22331/q-2021-09-28-553

Topological protection is employed in fault-tolerant error correction and in developing quantum algorithms with topological qubits. But, topological protection $textit{intrinsic to models being simulated}$, also robustly protects calculations, even on NISQ hardware. We leverage it by simulating Kitaev-inspired models on IBM quantum computers and accurately determining their phase diagrams. This requires constructing conventional quantum circuits for Majorana braiding to prepare the ground states of Kitaev-inspired models. The entanglement entropy is then measured to calculate the quantum phase boundaries. We show how maintaining particle-hole symmetry when sampling through the Brillouin zone is critical to obtaining high accuracy. This work illustrates how topological protection intrinsic to a quantum model can be employed to perform robust calculations on NISQ hardware, when one measures the appropriate protected quantum properties. It opens the door for further simulation of topological quantum models on quantum hardware available today.