Topology and disorder have a rich combined influence on quantum transport. To probe their interplay, we synthesized one-dimensional chiral symmetric wires with controllable disorder via spectroscopic Hamiltonian engineering, based on the laser-driven coupling of discrete momentum states of ultracold atoms. Measuring the bulk evolution of a topological indicator after a sudden quench, we observed the topological Anderson insulator phase, in which added disorder drives the band structure of a wire from topologically trivial to nontrivial. In addition, we observed the robustness of topologically nontrivial wires to weak disorder and measured the transition to a trivial phase in the presence of strong disorder. Atomic interactions in this quantum simulation platform may enable realizations of strongly interacting topological fluids.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1126/science.aat3406 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Disorder-induced phase transitions in a two-dimensional magnetic topological insulator system.
J Phys Condens Matter
December 2024
School of Physics and Technology, University of Jinan, Jinan, Shandong 250022, People's Republic of China.
We investigate the phase diagram of a two-dimensional magnetic topological system in the parameter space of uncorrelated Anderson disorder and Zeeman splitting energy. In the absence of disorder, the system undergoes the phases of higher-order topological insulators (HOTIs), Chern insulators (CIs) with Chern numbers = 2 and = 1, and band insulators successively with enhancing Zeeman energy. The phase boundary separating these phases is found to be strongly deformed by the disorder, which leads to several topological Anderson insulators.
View Article and Find Full Text PDFTopological Effect on the Anderson Transition in Chiral Symmetry Classes.
Phys Rev Lett
November 2024
International Center for Quantum Materials, Peking University, Beijing 100871, China.
In this Letter, we propose a mechanism of an emergent quasilocalized phase in chiral symmetry classes, where the wave function along a spatial direction with weak topology is delocalized but exponentially localized along the other directions. The Anderson transition in two-dimensional chiral symmetry classes is induced by the proliferation of vortex-antivortex pairs of a U(1) phase degree of freedom, while the weak topology endows the pair with a Berry phase. We argue that the Berry phase induces spatial polarizations of the pairs along the topological direction through the quantum interference effect, and the proliferation of the polarized vortex pairs results in the quasilocalized phase.
View Article and Find Full Text PDFArticle Synopsis
- Guanine-rich nucleic acid sequences can impact biological processes, exhibiting both cytotoxic and cytoprotective effects, though the underlying mechanisms are not fully understood.
- This study focuses on G-rich DNA oligonucleotides that form G-quadruplexes (G4s) and reveals that their biological effects depend on their structure; specifically, only parallel G4s can inhibit eukaryotic translation by interacting with the translation initiation protein EIF4G1.
- This research establishes a direct link between the topology of G4s and their functional outcomes, paving the way for the design of G-rich oligonucleotides for therapeutic applications.
Direct magnetic imaging of fractional Chern insulators in twisted MoTe.
Nature
November 2024
Department of Physics, University of California Santa Barbara, Santa Barbara, CA, USA.
Orbital magnetization provides a sensitive probe of topology and interactions, with particularly rich phenomenology in Chern insulators in which the topological edge states carry large equilibrium currents. Here we use a nanoscale superconducting sensor to map the magnetic fringe fields in twisted bilayers of MoTe, in which transport and optical sensing experiments have revealed the formation of fractional Chern insulator (FCI) states at zero magnetic field. We observe oscillations in the local magnetic field associated with fillings ν = -1, -2/3, -3/5, -4/7 and -5/9 of the first moiré hole band, consistent with the formation of FCIs at these fillings.
View Article and Find Full Text PDFTrion sensing of a zero-field composite Fermi liquid.
Nature
November 2024
Department of Physics, University of Washington, Seattle, WA, USA.
The half-filled lowest Landau level is a fascinating platform for researching interacting topological phases. A celebrated example is the composite Fermi liquid, a non-Fermi liquid formed by composite fermions in strong magnetic fields. Its zero-field counterpart is predicted in a twisted MoTe bilayer (tMoTe)-a recently discovered fractional Chern insulator exhibiting the fractional quantum anomalous Hall effect.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!