□ A research team led by Professor JaeDong Lee of the Department of Physics and Chemistry at DGIST (President Kunwoo Lee) has, for the first time in the world, elucidated the microscopic mechanism by which quantum order is lost and collapses in “open quantum environments” existing in nature. Since perfectly isolated quantum systems cannot exist in reality, this study is expected to provide a decisive breakthrough in bridging the gap between ideal quantum theory and quantum technologies that must operate in real-world environments.
□ “High-order harmonics,” generated when intense light is irradiated onto solid materials, have high academic and industrial value, as they are used for material characterization as well as for generating ultrafast pulses and high-energy light. However, during this process, a phenomenon known as “ultrafast electronic decoherence” occurs, in which the intrinsic quantum state becomes disrupted within an extremely short timescale of 1–2 femtoseconds (10⁻¹⁵ seconds). The fundamental cause of this phenomenon had remained unknown despite more than a decade of extensive research worldwide.
□ To solve this puzzle, Professor JaeDong Lee’s team developed and applied a novel computational approach based on the “Lindblad master equation,” overcoming the limitations of conventional quantum master equations. This enabled the establishment of a microscopic theoretical research framework that can precisely account for not only electron–electron interactions but also interactions between electrons and their surrounding environment.
□ The team analyzed the phenomena of “superradiance” and “broadband emission” observed in the process of high-order harmonic generation in solids, and newly found that interference occurs between the two, leading to mutual cancellation. As a result, they confirmed that interactions with the environment (such as superradiance) in open quantum environments play a decisive role in governing ultrafast electronic decoherence in solids, thereby resolving a long-standing challenge in the field.
□ “Through this study, we have found that ultrafast electronic decoherence in solids—long regarded as a mystery for over a decade—originates from environmental interactions in open quantum systems,” stated Professor JaeDong Lee of the Department of Physics and Chemistry at DGIST. “The true significance of this research lies in opening a pathway to connect ideal quantum theory to practical and reliable quantum engineering, and it will pose a new and substantial challenge to existing quantum technology concepts based on the assumption of isolated quantum systems.”
□ Meanwhile, this study was supported by the Mid-Career Researcher Support Program of the National Research Foundation of Korea and DGIST’s International Collaborative Research Program. The research findings (first author: Dr. Gimin Bae of the DGIST Department of Physics and Chemistry) were published in the leading interdisciplinary science journal Advanced Science .
Advanced Science
Superradiance and Broadband Emission Driving Fast Electron Dephasing in Open Quantum Systems
10-Mar-2026