Qdev seminar by Alex Greene, Massachusetts Institute of Technology

Characterization and Automated Calibration of CPHASE Gates on a Grid of 27 Transmon Superconducting Qubits

The promise of quantum advantage over classical hardware has driven impressive strides in the field of quantum computing over the past two decades, and there is an increasing interest in exploring quantum applications on noisy intermediate-scale quantum (NISQ) devices available in near term. 

In superconducting qubits, the error-rates of single-qubit gates are generally an order of magnitude lower than those of two-qubit gates and consequently, a typical strategy for running quantum programs has been to compile the circuits using a minimal universal gate set consisting of several single-qubit gates and one two-qubit gate.

However, parametrized families of two-qubit gates can enhance the capabilities of NISQ hardware by lowering circuit depth. In this talk, we discuss the automated calibration and characterization of a family of CPHASE gates [1,2] on a grid of 27 transmon superconducting qubits, which has enabled the study of many-body localization discrete time crystals on a quantum processor [3].

Bio:

Alex Greene works with superconducting qubits as a senior graduate student in Will Oliver's group at MIT. Alex's research focuses on reducing and mitigating errors in two-qubit gates.

References:

[1] A tunable coupling scheme for implementing high-fidelity two-qubit gates. Phys. Rev. Applied 10, 054062 (2018)

[2] Demonstrating a Continuous Set of Two-qubit Gates for Near-term Quantum Algorithms. Phys. Rev. Lett. 125, 120504 (2020).

[3] Observation of Time-Crystalline Eigenstate Order on a Quantum Processor. Nature 60, 531 (2022)