RQC Seminar

63rd RQC Seminar

• Speaker

  Prof. Britton Plourde
  ( Physics Department, Syracuse University )

• Date

  16:00-17:00, July 21st, 2023 (Friday)

• Venue

  Hybrid(ZOOM・ Wako Main Research 3F 345-347 Seminar Room)

• Title

  Hardware implementation of quantum stabilizers for protecting qubits from decoherence

• Inquiries

  rqc_info[at]ml.riken.jp

Abstract
The coherence times of superconducting qubits have undergone tremendous growth over the past two decades through a combination of materials science efforts and improvements in device design and measurement. Moving significantly beyond the current state-of-the-art coherence achievable with present-day qubits will require new device designs. Circuits that have a natural topological protection against decoherence due to local noise are particularly attractive. The 0-pi qubit was an early example of such a protected design and was based on a composite superconducting circuit element with an unusual pi-periodic dependence on the superconducting phase difference. However, the practical requirements for building this circuit element are extremely challenging, which has made the 0-pi design quite difficult to implement. More recently, a new qubit design composed of chains of concatenated imperfect pi-periodic Josephson elements has offered a more feasible approach to achieving protection. In this case, the level of protection against local noise increases exponentially with the number of concatenated pi-periodic elements. This is equivalent to implementing stabilizer operations, which are at the heart of quantum error correction, directly in hardware.