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Related papers: Measuring Chern numbers in Hofstadter strips

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Topologically ordered phase has emerged as one of most exciting concepts that not only broadens our understanding of phases of matter, but also has been found to have potential application in fault-tolerant quantum computation. The direct…

Quantum Physics · Physics 2016-06-01 Zhihuang Luo , Chao Lei , Jun Li , Xinfang Nie , Zhaokai Li , Xinhua Peng , Jiangfeng Du

It is still an outstanding challenge to characterize and understand the topological features of strongly interacting states such as bound-states in interacting quantum systems. Here, by introducing a cotranslational symmetry in an…

Quantum Gases · Physics 2017-11-17 Xizhou Qin , Feng Mei , Yongguan Ke , Li Zhang , Chaohong Lee

We propose a method of measuring topological invariants of a photonic crystal through phase spectroscopy. We show how the Chern numbers can be deduced from the winding numbers of the reflection coefficient phase. An explicit proof of…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 A. V. Poshakinskiy , A. N. Poddubny , M. Hafezi

Local topological markers, topological invariants evaluated by local expectation values, are valuable for characterizing topological phases in materials lacking translation invariance. The Chern marker -- the Chern number expressed in terms…

Mesoscale and Nanoscale Physics · Physics 2023-01-11 Julia D. Hannukainen , Miguel F. Martinez , Jens H. Bardarson , Thomas Klein Kvorning

Topological materials rely on engineering global properties of their bulk energy bands called topological invariants. These invariants, usually defined over the entire Brillouin zone, are related to the existence of protected edge states.…

Mesoscale and Nanoscale Physics · Physics 2021-03-31 P. St-Jean , A. Dauphin , P. Massignan , B. Real , O. Jamadi , M. Milićević , A. Lemaître , A. Harouri , L. Le Gratiet , I. Sagnes , S. Ravets , J. Bloch , A. Amo

Recent experiments began to explore the topological properties of quench dynamics, i.e. the time evolution following a sudden change in the Hamiltonian, via tomography of quantum gases in optical lattices. In contrast to the well…

Mesoscale and Nanoscale Physics · Physics 2020-04-23 Haiping Hu , Erhai Zhao

We study amorphous systems with completely random sites and find that, through constructing and exploring a concrete model Hamiltonian, such a system can host an exotic phase of topological amorphous metal in three dimensions. In contrast…

Mesoscale and Nanoscale Physics · Physics 2019-08-21 Yan-Bin Yang , Tao Qin , Dong-Ling Deng , L. -M. Duan , Yong Xu

In this work, we report original properties inherent to independent particles subjected to a magnetic field by emphasizing the existence of regular structures in the energy spectrum's outline. We show that this fractal curve, the well-known…

Mesoscale and Nanoscale Physics · Physics 2009-07-14 N. Goldman

The central goal of this thesis is to develop methods to experimentally study topological phases. We do so by applying the powerful toolbox of quantum simulation techniques with cold atoms in optical lattices. To this day, a complete…

Quantum Gases · Physics 2017-09-26 Samuel Mugel

Topological invariants are crucial for characterizing topological systems. However, experimentally measuring them presents a significant challenge, especially in non-Hermitian systems where the biorthogonal eigenvectors are often necessary.…

Quantum Physics · Physics 2025-04-23 Shuo Wang , Zhengjie Kang , Hao Li , Jiaojiao Li , Yuanjie Zhang , Zhihuang Luo

The topology of one-dimensional chiral systems is captured by the winding number of the Hamiltonian eigenstates. Here we show that this invariant can be read-out by measuring the mean chiral displacement of a single-particle wavefunction…

Topological materials are characterized by integer invariants that underpin their robust quantized electronic features, as famously exemplified by the Chern number in the integer quantum Hall effect. Yet, in most candidate systems, the…

Mesoscale and Nanoscale Physics · Physics 2025-08-27 Yuval Abulafia , Eric Akkermans

In crystalline systems with a superstructure, the electron dispersion can form a nontrivial covering of the Brillouin zone. It is proved that the number of sheets in this covering and its monodromy are topological invariants under ambient…

Other Condensed Matter · Physics 2026-04-30 Yu. B. Kudasov

A hallmark feature of topological physics is the presence of one-way propagating chiral modes at the system boundary. The chirality of edge modes is a consequence of the topological character of the bulk. For example, in a non-interacting…

Mesoscale and Nanoscale Physics · Physics 2016-03-02 Sunil Mittal , Sriram Ganeshan , Jingyun Fan , Abolhassan Vaezi , Mohammad Hafezi

We propose a scheme for measuring topological properties in a two-photon-driven Kerr-nonlinear resonator (KNR) subjected to a single-photon modulation. The topological properties are revealed through the observation of the Berry curvature…

Quantum Physics · Physics 2024-07-16 Bi-Yao Wang , Hao-Long Zhang , Shou-Bang Yang , Fan Wu , Zhen-Biao Yang , Shi-Biao Zheng

The appearance of fractional Chern insulators in moir\'e systems can be rationalized by the presence of a fictitious magnetic field associated with the spatial texture of layer-resolved electronic wavefunctions. Here, we present a…

Mesoscale and Nanoscale Physics · Physics 2025-07-02 Kryštof Kolář , Kang Yang , Felix von Oppen , Christophe Mora

Chern-Simons (CS) invariant is a fundamental topological invariant describing the topological invariance of 3D space based on the Chern-Simons field theory. To date, direct measurement of the CS invariant in a physical system remains…

Quantum Gases · Physics 2025-09-09 Chang-Rui Yi , Jinlong Yu , Huan Yuan , Xin Chen , Jia-Yu Guo , Jinyi Zhang , Shuai Chen , Jian-Wei Pan

Topological phase transitions are typically characterized by abrupt changes in a quantized invariant. Here we report a contrasting paradigm in non-Hermitian parity-time symmetric systems, where the topological invariant remains conserved,…

Mesoscale and Nanoscale Physics · Physics 2025-03-31 Kang Yang , Zhi Li , Peng Xue , Emil J. Bergholtz , Piet W. Brouwer

The accurate determination of non-Hermitian (NH) topological invariants plays a central role in the study of NH topological phases. In this work, we propose a general framework for directly measuring NH topological invariants in…

Quantum Gases · Physics 2025-09-16 Xiao-Dong Lin , Long Zhang

Topology plays a central role in nearly all disciplines of physics, yet its applications have so far been restricted to closed, lossless systems in thermodynamic equilibrium. Given that many physical systems are open and may include gain…

Mesoscale and Nanoscale Physics · Physics 2019-08-21 Mark R. Hirsbrunner , Timothy M. Philip , Matthew J. Gilbert