In physics, “universality” refers to a property of a system that does not depend on details. Establishing the universality of quantum mechanics is one of the important concerns of theoretical physicists. Currently, Japanese researchers have identified such universality in chaotic quantum systems, characterized by one-parameter scaling of surface roughness and entanglement entropy (a measure of quantum entanglement).
Real-world multi-particle systems are often infused with “disorder” or “randomness.” This in turn leads to the occurrence of such system-specific phenomena. For example, the electrons of a strong and chaotic system Destructive interference, A phenomenon known as “Anderson localization”.
Anderson localization has been extensively studied in terms of one-parameter scaling, where system properties are scaled based on one particular parameter. However, while most studies focus on static properties, disorder can also have a significant impact on quantum dynamics such as entanglement dynamics and transport phenomena.
In a recent study published in Physical review letter, A team of physicists led by Professor Kazuya Fujimoto of Nagoya University has numerically demonstrated dynamic one-parameter scaling called “Family Bichek (FV) scaling” of chaotic quantum systems. “FV scaling was originally known from classics, Water surface During the growth, we discovered the scaling of random quantum systems by introducing the “quantum surface height operator”, “explains Professor Fujimoto.
In their study, physicists examined a system of non-interacting spinless fermions in the chaotic one-dimensional potential of three common models. They found that the surface roughness follows FV scaling, which is characterized by three indices. Further numerical analysis showed that surface roughness may be related to entanglement entropy (EE), showing FV type scaling of EE. In addition, they observed an anomalous scaling index in one of the models and attributed it to the presence of localized states in the delocalized phase. This is a classic feature of quantum disorder systems.
The important thing is Surface roughness Microscopic techniques can be used to make experimental measurements of cold atom systems. This allows experimental estimation of EE to be performed on non-interacting fermions.
“These discoveries provide a better understanding of non-equilibrium physics and provide a new perspective for classifying universal non-equilibrium phenomena that emerge in random quantum systems,” says Professor Fujimoto.
Kazuya Fujimoto et al., Dynamic scaling of surface roughness and entanglement entropy in chaotic fermion models, Physical review letter (2021). DOI: 10.1103 / PhysRevLett.127.090601
Quote: Dynamic scaling of entanglement entropy and surface roughness in a random quantum system (2021, October 26) is available at https://phys.org/news/2021-10-dynamical-scaling-entanglement-entropy-surface. Obtained from html on October 26, 2021.
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Dynamic scaling of entanglement entropy and surface roughness in random quantum systems
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