Dissipation-Induced Criticality and Nonequilibrium Topology

  • Event Date: 2026-05-13
  • Quantum information and communication
  • Speaker: Dr. Kai-Chen Yang (Eddleman Quantum Institute, University of California, Irvine, CA, USA)  /  Host: Prof. Yueh-Nan Chen (NCKU)
    Place: R36169, 1F, Dept. of Physics, Building of Science College, NCKU

Time:14:00, Wednesday, May 13, 2026
Speaker:Dr. Kai-Chen Yang
              Eddleman Quantum Institute, University of California, Irvine, CA, USA
Title: Dissipation-Induced Criticality and Nonequilibrium Topology
Place : R36169, 1F, Dept. of Physics, Building of Science College, NCKU

Abstract:
Dissipation, often viewed as a nuisance, can instead be harnessed as a resource in quantum devices. We first introduce a new universality class unique to open quantum systems, governed by a complex conformal field theory [1]. A broad class of non-Hermitian 1+1D quantum systems with O(N) symmetry flows to this critical phase, which hosts an emergent, dissipation-induced non-invertible symmetry. We then show how similar principles resolve longstanding concerns about the survivability of periodically driven Floquet systems. Here, dissipation not only stabilizes light-induced phases, but also enables controllable many-body responses, including a tunable Hall effect in twisted bilayer graphene [2], a quantized nonadiabatic charge pump in phonon-driven systems [3], and the first experimental signatures of Floquet many-body steady states in graphene [4]. We conclude with predictions for quantum devices such as lasers, where the active medium can by design self-organize into a topological insulator. Across these examples, dissipation emerges as a design principle for open quantum matter.

 

[1] CY, T. Scaffidi, “Asymptotic freedom, lost: Complex conformal field theory in the two-dimensional O(N>2) nonlinear sigma model and its realization in the spin-1 Heisenberg chain,” arXiv:2601.02459 (2026)

[2] CY, I. Esin, C. Lewandowski, G. Refael, “Optical Control of Slow Topological Electrons in Moire Materials,” Physical Review Letters 131, 026901 (2023)

[3] CY, W. Hunt, G. Refael, I. Esin, “Quantized Acoustoelectric Floquet Effect in Quantum Nanowires,” Physical Review Letters 133, 226301 (2024)

[4] Y. Liu, CY, et al. “Signatures of Floquet electronic steady states in graphene under continuous-wave mid-infrared irradiation,” Nature Communications, 16, 2057 (2025)

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