Group seminar at MPQ and Zoom: Design of time-optimal high-fidelity gates

Chenhuarui Cao, Peking University, China
Group seminar at MPQ lecture hall & Zoom
Tuesday, 17 June, 09:00 am (MEZ)

In recent years, quantum computing on ultracold atom systems is becoming more and more important, while applying high-fidelity multi-qubit gates is a core problem in quantum computing. Using the three-level model of atoms, our work uses symmetry to reduce the dimension of the Hilbert space and simplify the Hamiltonian. After that, we construct the GRAPE algorithm to design and optimize the time and fidelity of multi-qubit phase gates. By investigating CnZ gates and 2-qubit phase gates when Rydberg blockade strength is infinity, we find that for all gates there exists a minimal gate time. Same conclusion is found when Rydberg blockade strength is finite, but the pulse shape is very different from the infinite case when blockade strength is approximately equal to the laser frequency. Our work provides insight on the design of general multi-qubit phase gates.