Kanta Masuki 교수

Dissipative quantum phase transition has been widely believed to occur in a Josephson junction coupled to a resistor despite a lack of concrete experimental evidence. Here, on the basis of both numerical and analytical nonperturbative renormalization group analyses, we reveal breakdown of previous perturbative arguments and defy the common wisdom that the transition always occurs at the quantum resistance R_{Q}=h/(4e^{2}). We find that renormalization group flows in nonperturbative regimes induc

Strong coupling between matter and quantized electromagnetic fields in a cavity has emerged as a possible route toward controlling the phase of matter in the absence of an external drive. We develop a faithful and efficient theoretical framework to analyze quantum geometry and topology in materials ultrastrongly coupled to cavity electromagnetic fields in two dimensions. The formalism allows us to accurately evaluate geometrical and topological quantities, such as Berry phase and Chern number, i

Cavity quantum electrodynamics (QED) studies the interaction between light and matter at the single quantum level and has played a central role in quantum science and technology. Combining the idea of cavity QED with moir\'e materials, the authors develop here a theory of cavity moir\'e materials, i.e., moir\'e materials confined in a cavity. These results indicate that the cavity confinement enables one to control magnetic frustration of moir\'e materials and might allow the realization of vari

Received 10 July 2023Accepted 9 October 2023DOI:https://doi.org/10.1103/PhysRevLett.131.199702© 2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasDissipative dynamicsJosephson effectQuantum phase transitionsQuantum transportSuperconductor-insulator transitionPhysical SystemsJosephson junctionsTechniquesFunctional renormalization groupNumerical Renormalization GroupCondensed Matter, Materials & Applied PhysicsStatistical Physics & Thermodynamics

We reply to the comments on our previous paper Physical Review Letters, Vol. 129, 087001 (2022), raised by Théo Sépulcre, Serge Florens, and Izak Snyman in arXiv:2210.00742.

Dissipative quantum phase transition has been widely believed to occur in a Josephson junction coupled to a resistor despite a lack of concrete experimental evidence. Here, on the basis of both numerical and analytical nonperturbative renormalization group (RG) analyses, we reveal breakdown of previous perturbative arguments and defy the common wisdom that the transition always occurs at the quantum resistance $R_{Q} \!=\! h/(4e^2)$. We find that RG flows in nonperturbative regimes induce nonmon

Diffusion models represent a class of generative models that produce data by denoising a sample corrupted by white noise. Despite the success of diffusion models in computer vision, audio synthesis, and point cloud generation, so far they overlook inherent multiscale structures in data and have a slow generation process due to many iteration steps. In physics, the renormalization group offers a fundamental framework for linking different scales and giving an accurate coarse-grained model. Here w

Strong coupling between matter and quantized electromagnetic fields in a cavity has emerged as a possible route toward controlling the phase of matter in the absence of an external drive. We develop a faithful and efficient theoretical framework to analyze quantum geometry and topology in materials ultrastrongly coupled to cavity electromagnetic fields in two dimensions. The formalism allows us to accurately evaluate geometrical and topological quantities, such as Berry phase and Chern number, i

Cavity quantum electrodynamics (QED) studies the interaction between light and matter at the single quantum level and has played a central role in quantum science and technology. Combining the idea of cavity QED with moiré materials, we theoretically show that strong quantum light-matter interaction provides a way to control frustrated magnetism. Specifically, we develop a theory of moiré materials confined in a cavity consisting of thin polar van der Waals crystals. We show that nontrivial quan