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Updated: Aug 28, 2025
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
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Direct geometric probe of singularities in band structure
Charles D Brown1,2,3, Shao-Wen Chang1,2, Malte N Schwarz1,2
1Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA.
Science (New York, N.Y.)
|September 15, 2022
Summary
Researchers probed quantum singularities using ultracold atoms in optical lattices. They measured topological winding numbers of band-touching points, revealing new insights into quantum system properties.
Area of Science:
- Quantum physics
- Condensed matter physics
- Atomic physics
Background:
- Quantum systems can feature degenerate energy surfaces with unique wave function geometry.
- These singularities significantly impact system properties.
- Ultracold atoms in optical lattices offer a platform for studying these phenomena indirectly.
Purpose of the Study:
- To directly measure the non-Abelian transformation produced by transport through quantum singularities.
- To characterize singularities at linear and quadratic band-touching points in a honeycomb lattice.
- To introduce a novel method for probing non-Dirac singularities in quantum simulators.
Main Methods:
- Transporting ultracold atoms along a specific quasi-momentum trajectory.
- Trajectory designed to enter, turn within, and exit singularities.
- Utilizing honeycomb optical lattice to create linear and quadratic band-touching points.
Main Results:
- Successfully measured non-Abelian transformations through the singularities.
- Identified topological winding numbers of 1 and 2 for the probed singularities.
- Demonstrated direct probing of band-touching point topology.
Conclusions:
- The study introduces a distinct experimental method for probing quantum singularities.
- This technique enables the study of non-Dirac singularities in ultracold-atom quantum simulators.
- Provides new avenues for understanding complex quantum phenomena.
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