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Berry curvature physics and quantum geometric effects have been instrumental in advancing topological condensed matter physics in recent decades. Although Landau level-based flat bands and conventional 3D solids have been pivotal in…

Mesoscale and Nanoscale Physics · Physics 2024-05-16 Pratap Chandra Adak , Subhajit Sinha , Amit Agarwal , Mandar M. Deshmukh

Superlattice potential modulation can produce flat minibands in Bernal-stacked bilayer graphene. In this work we study how band topology and interaction-induced symmetry-broken phases in this system are controlled by tuning the displacement…

Mesoscale and Nanoscale Physics · Physics 2024-07-04 Yongxin Zeng , Tobias M. R. Wolf , Chunli Huang , Nemin Wei , Sayed Ali Akbar Ghorashi , Allan H. MacDonald , Jennifer Cano

Since the discovery of magic-angle twisted bilayer graphene (TBG), flat bands in Dirac materials have become a prominent platform for realizing strong correlation effects in electronic systems. Here we show that the symmetry group…

Strongly Correlated Electrons · Physics 2023-12-20 Yarden Sheffer , Raquel Queiroz , Ady Stern

Topological phases play a crucial role in the fundamental physics of light-matter interaction and emerging applications of quantum technologies. However, the topological band theory of waveguide QED systems is known to break down, because…

Optics · Physics 2023-12-08 Yongguan Ke , Jiaxuan Huang , Wenjie Liu , Yuri Kivshar , Chaohong Lee

We investigate the quantum geometric tensor, which is comprised of the Berry curvature and quantum metric, in a generalized Dirac two-band system with non-integer dispersion $E(\mathbf{k})\sim k^{\alpha}$. Our analysis reveals that this…

Superconductivity · Physics 2025-06-03 Jamme Omar A. Biscocho , Kristian Hauser A. Villegas

We introduce a method of reverse holography by which a bulk metric is shown to arise from locally computable multiscale correlations of a boundary quantum field theory (QFT). The metric is obtained from the Petz-R\'enyi mutual information…

We numerically investigate and experimentally demonstrate an in-situ topological band transition in a highly tunable mechanical system made of cylindrical granular particles. This system allows us to tune its inter-particle stiffness in a…

Pattern Formation and Solitons · Physics 2017-07-19 Rajesh Chaunsali , Aman Thakkar , Eunho Kim , Panayotis G. Kevrekidis , Jinkyu Yang

Topology is a central notion in the classification of band insulators and characterization of entangled many-body quantum states. In some cases, it manifests as quantized observables such as quantum Hall conductance. However, being…

Strongly Correlated Electrons · Physics 2022-08-26 Sangjin Lee , Kyung-Hwan Jin , Byungmin Kang , B. J. Kim , Gil Young Cho

The importance of the quantum metric in flat-band systems has been noticed recently in many contexts such as the superfluid stiffness, the dc electrical conductivity, and ideal Chern insulators. Both the quantum metric of degenerate and…

Mesoscale and Nanoscale Physics · Physics 2022-11-10 Bruno Mera , Johannes Mitscherling

Topological flat bands at the Fermi level offer a promising platform to study a variety of intriguing correlated phase of matter. Here we present band engineering in the twisted orbital-active bilayers with spin-orbit coupling. The symmetry…

Mesoscale and Nanoscale Physics · Physics 2022-09-15 Huan Wang , Yadong Jiang , Zhaochen Liu , Jing Wang

Quantum metrology is deeply connected to quantum geometry, through the fundamental notion of quantum Fisher information. Inspired by advances in topological matter, it was recently suggested that the Berry curvature and Chern numbers of…

Quantum Physics · Physics 2024-11-12 Min Yu , Xiangbei Li , Yaoming Chu , Bruno Mera , F. Nur Ünal , Pengcheng Yang , Yu Liu , Nathan Goldman , Jianming Cai

The interplay between topological phases of matter and dissipative baths constitutes an emergent research topic with links to condensed matter, photonic crystals, cold atomic gases and quantum information. While recent studies suggest that…

Strongly Correlated Electrons · Physics 2015-10-28 Kush Saha , Katherine Légaré , Ion Garate

We study the effects of heterostrain on moir\'e bands in twisted bilayer graphene and bilayer transition metal dichalcogenide (TMD) systems. For bilayer graphene with twist angle near $1^\circ$, we show that heterostrain significantly…

Materials Science · Physics 2019-08-07 Zhen Bi , Noah F. Q. Yuan , Liang Fu

The topological mechanics is a perfect tool that can bridge the gap between the quantum and Newtonian physics and mechanics of materials. It requires discrete models of the material with analogies with the topological characteristics of…

Applied Physics · Physics 2020-06-02 Mohamed Shaat

We theoretically propose a design for two-dimensional Dirac semimetals using a bilayer-modified Bernevig-Hughes-Zhang (BHZ) model. By introducing new sites into the BHZ model, we engineer flat bands at the Fermi energy. In the bilayer…

Mesoscale and Nanoscale Physics · Physics 2025-09-08 Lizhou Liu , Cheng-Ming Miao , Qing-Feng Sun , Ying-Tao Zhang

Three-dimensional (3D) topological insulators (TI) are novel quantum materials with insulating bulk and topologically protected metallic surfaces with Dirac-like band structure. The spin-helical Dirac surface states are expected to host…

We consider quantum rings realized in materials where the dynamics of charge carriers mimics that of two-dimensional (2D) Dirac electrons. A general theoretical description of the ring-subband structure is developed that applies to a range…

Mesoscale and Nanoscale Physics · Physics 2018-05-17 L. Gioia , U. Zülicke , M. Governale , R. Winkler

We uncover a useful connection between the integrated current noise $S(\omega)$ and the topological band gap in dispersionless quantum states, $\int d \omega [ \mathcal S^{\text{flat}}_{xx} + \mathcal S^{\text{flat}}_{yy} ] = C e^2…

Strongly Correlated Electrons · Physics 2023-09-04 Alexander Kruchkov , Shinsei Ryu

We use temperature-dependent resistivity in small-angle twisted double bilayer graphene to measure bandwidths and gaps of the bands. This electron-hole asymmetric system has one set of non-dispersing bands that splits into two flat bands…

The motion of a quantum particle constrained to a two-dimensional non-compact Riemannian manifold with non-trivial metric can be described by a flat-space Schroedinger-type equation at the cost of introducing local mass and metric and…

Mesoscale and Nanoscale Physics · Physics 2025-12-19 Benjamin Schwager , Theresa Appel , Jamal Berakdar