Speaker: Dr. Pedram Roushan

Host: Zhu-Xi Luo

Title:  Novel quantum dynamics with superconducting qubits

Abstract: In recent years, superconducting qubits have emerged as a leading platform for quantum simulation of non-equilibrium dynamics on Noisy Intermediate-Scale Quantum (NISQ) processors. I will discuss some of our recent work in this area. Motivated by questions in high-energy physics, we directly image the dynamics of charges and strings in (2+1)-dimensional lattice gauge theories [1], revealing two distinct regimes within the confining phase: a weak-confinement regime where the string exhibits strong transverse fluctuations, and a strong-confinement regime where these fluctuations are significantly suppressed. Turning to condensed matter physics, in another study [2] we observe a novel form of localization in quantum many-body systems in one and two dimensions. The dynamics exhibit a striking absence of energy diffusion even when the evolution operator is disorder-free and the initial states are fully translationally invariant. These results demonstrate that NISQ processors, even short of fault-tolerant quantum computers, are powerful tools for probing non-equilibrium quantum phenomena and advancing our understanding of complex quantum dynamics.

[1] Cochran et al., Nature 642, 315–320 (2025)

[2] Gyawali  et al., arxiv.org/abs/2410.06557

Bio: Pedram Roushan is a Staff Research Scientist at Google Quantum AI, where he leads experimental efforts on Noisy Intermediate-Scale Quantum (NISQ) algorithms, focusing on simulating complex quantum phenomena. He received his PhD in 2011 from Princeton University, where he worked under the supervision of Ali Yazdani and performed the first scanning tunneling microscopy measurements on the surface of topological insulators. He later joined John Martinis’s group at the University of California, Santa Barbara, as a postdoctoral researcher, developing superconducting qubits and quantum computing architectures. He subsequently moved to Google, where he contributed to the first demonstration of quantum supremacy in 2019. His current work focuses on simulating non-equilibrium dynamics, and he coined the term “discoverino” to describe early discoveries made on NISQ devices.