RQC Seminar

267th RQC Seminar

• Speaker

  Mr. Leo Goutte
  ( The Swiss Federal Institute of Technology in Lausanne (EPFL) )

• Date

  14:00-15:00, (2:00 p.m.-3:00 p.m.) Tuesday, April 21, 2026

• Venue

  Hybrid( Zoom,
  345-347 Seminar Room, 3F, Main Research Building, Wako Campus / 和光地区 研究本館3階 セミナー室 (345-347) (C01))

• Title

  Low-rank transmon readout

• Inquiries

  norilab_rqc_assist[at]ml.riken.jp

Abstract
Quantum computing promises transformative advances in cryptography, quantum chemistry, and optimization. Simulating open quantum systems remains one of the main bottlenecks in achieving and optimizing these quantum devices [1]. Conventional methods, however, quickly become prohibitively expensive when strong drives and dissipation are involved — precisely the regime in which quantum computing takes place. In this talk, I’ll present a low-rank method that captures the full quantum dynamics at a fraction of the computational cost. I’ll show how this approach is particularly well-suited to the task of optimal control for quantum computing, outperforming traditional approximations such as the rotating-wave approximation. Finally, I will consider the timely example of reading out a superconducting transmon qubit through a resonator and a Purcell filter, complete with a drive-pulse optimization of the readout fidelity consistent with the state-of-the-art [2].
1. R. Gautier, E. Genois, and A. Blais, Physical Review Letters 134, 070802 (2025), publisher: American Physical Society, URL https://link.aps.org/doi/10.1103/PhysRevLett.134.070802
2. L. Goutte and V. Savona, https://arxiv.org/pdf/2508.18114.