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Topological Transverse Transport without a Gap in Critical Topological Flat Bands
Chang-geun Oh, Tomoki Ozawa, Jun-Won Rhim
Quantized Hall transport is traditionally anchored to a bulk spectral gap, which isolates the occupied subspace and exponentially suppresses thermal deviations. Recently discovered…
Non-Abelian Gauge Field Mechanics
Ivan Velkovsky, Carlos Camacho, Tomoki Ozawa +2
Non-Abelian gauge fields play a key role in describing the behavior of particles whose motion is coupled to internal degrees of freedom, such as their spin. Here, we experimentally…
Hall viscosity from metric-sensitive dichroic probes
Alberto Nardin, Bruno Mera, Anaïs Defossez +3
Hall viscosity characterizes the geometric response of a quantum Hall droplet to deformations of the underlying metric, yet it has remained difficult to measure directly. We propos…
Relaxation toward an Ideal Chern Band through Coupling to a Markovian Bath
Bruno Mera, Tomoki Ozawa
We propose a microscopic, weak-coupling mechanism by which generic Chern bands asymptotically relax toward ideal bands. We consider coupling interacting electrons to a Caldeira-Leg…
Density Matrix Geometry and Sum Rules
Guangyue Ji, David E. Palomino, Nathan Goldman +4
Geometry plays a fundamental role in a wide range of physical responses, from anomalous transport coefficients to their related sum rules. Notable examples include the quantization…
Geometrical Responses of Generalized Landau Levels: Structure Factor and the Quantized Hall Viscosity
Carolina Paiva, Jie Wang, Tomoki Ozawa +1
We present a new geometric characterization of generalized Landau levels (GLLs). The GLLs are a generalization of Landau levels to non-uniform Berry curvature, and are mathematical…
Exact Parent Hamiltonians for All Landau Level States in a Half-flux Lattice
Xin Shen, Guangyue Ji, Jinjie Zhang +4
Realizing topological flat bands with tailored single-particle Hilbert spaces is a critical step toward exploring many-body phases, such as those featuring anyonic excitations. One…
Observation of chiral solitary waves in a nonlinear Aharonov-Bohm ring
Ivan Velkovsky, Anya Abraham, Enrico Martello +7
Nonlinearities can have a profound influence on the dynamics and equilibrium properties of discrete lattice systems. The simple case of two coupled modes with self-nonlinearities g…
Theory of Generalized Landau Levels and Implication for non-Abelian States
Zhao Liu, Bruno Mera, Manato Fujimoto +2
Quantum geometry is a fundamental concept to characterize the local properties of quantum states. It is recently demonstrated that saturating certain quantum geometric bounds allow…
Relating the Hall conductivity to the many-body Chern number using Fermi's Golden rule and Kramers-Kronig relations
Nathan Goldman, Tomoki Ozawa
This pedagogical piece provides a surprisingly simple demonstration that the quantized Hall conductivity of correlated insulators is given by the many-body Chern number, a topologi…
Bulk-entanglement spectrum correspondence in - and -symmetric topological insulators and superconductors
Ryo Takahashi, Tomoki Ozawa
In this study, we discuss a new type of bulk-boundary correspondence which holds for topological insulators and superconductors when the parity-time () and/or parity-particle-h…
Two-dimensional lattice with an imaginary magnetic field
Tomoki Ozawa, Tomoya Hayata
We introduce a two-dimensional non-Hermitian lattice model with an imaginary magnetic field and elucidate various unique features which are absent in Hermitian lattice models with…
Bulk-edge correspondence of Stiefel-Whitney and Euler insulators through the entanglement spectrum and cutting procedure
Ryo Takahashi, Tomoki Ozawa
We propose an unconventional bulk-edge correspondence for two-dimensional Stiefel-Whitney insulators and Euler insulators, which are topological insulators protected by the sy…
Uniqueness of Landau levels and their analogs with higher Chern numbers
Bruno Mera, Tomoki Ozawa
Landau levels are the eigenstates of a charged particle in two dimensions under a magnetic field, and are at the heart of the integer and fractional quantum Hall effects, which are…
Coexistence of stable and unstable population dynamics in a nonlinear non-Hermitian mechanical dimer
Enrico Martello, Yaashnaa Singhal, Bryce Gadway +2
Non-Hermitian two-site ``dimers'' serve as minimal models in which to explore the interplay of gain and loss in dynamical systems. In this paper, we experimentally and theoreticall…
Singular connection approach to topological phases and resonant optical responses
Bruno Mera, Tomoki Ozawa
We introduce a class of singular connections as an alternative to the Berry connection for any family of quantum states defined over a parameter space. We find a natural applicatio…
Measuring the Adiabatic Non-Hermitian Berry Phase in Feedback-Coupled Oscillators
Yaashnaa Singhal, Enrico Martello, Shraddha Agrawal +3
The geometrical Berry phase is key to understanding the behaviour of quantum states under cyclic adiabatic evolution. When generalised to non-Hermitian systems with gain and loss,…
Synthetic Mechanical Lattices with Synthetic Interactions
Ritika Anandwade, Yaashnaa Singhal, Sai Naga Manoj Paladugu +8
Metamaterials based on mechanical elements have been developed over the past decade as a powerful platform for exploring analogs of electron transport in exotic regimes that are ha…
Engineering geometrically flat Chern bands with Fubini-Study Kähler structure
Bruno Mera, Tomoki Ozawa
We describe a systematic method to construct models of Chern insulators whose Berry curvature and the quantum volume form coincide and are flat over the Brillouin zone; such models…
Kähler geometry and Chern insulators: Relations between topology and the quantum metric
Bruno Mera, Tomoki Ozawa
We study Chern insulators from the point of view of Kähler geometry, i.e. the geometry of smooth manifolds equipped with a compatible triple consisting of a symplectic form, an int…
Relations between topology and the quantum metric for Chern insulators
Tomoki Ozawa, Bruno Mera
We investigate relations between topology and the quantum metric of two-dimensional Chern insulators. The quantum metric is the Riemannian metric defined on a parameter space induc…
Semi-Dirac Transport and Anisotropic Localization in Polariton Honeycomb Lattices
B. Real, O. Jamadi, M. Milićević +11
Compression dramatically changes the transport and localization properties of graphene. This is intimately related to the change of symmetry of the Dirac cone when the particle hop…
Direct observation of photonic Landau levels and helical edge states in strained honeycomb lattices
O. Jamadi, E. Rozas, G. Salerno +9
We report the realization of a synthetic magnetic field for photons and polaritons in a honeycomb lattice of coupled semiconductor micropillars. A strong synthetic field is induced…
Synthetic dimensions and topological chiral currents in mesoscopic rings
Hannah M. Price, Tomoki Ozawa, Henning Schomerus
The recently-introduced concept of "synthetic dimensions" allows for the realization of higher-dimensional topological phenomena in lower-dimensional systems. In this work we study…