AI Article Synopsis
- Electron-hole pairing in a dilute semimetal can lead to an excitonic insulator state, creating a gap at the Fermi surface similar to BCS superconductivity.
- Research on an InAs/GaSb quantum-well system shows compelling optical and electronic evidence of this gap formation at low temperatures and low electron-hole densities.
- Findings include terahertz transmission spectra that match BCS gap predictions and electronic transport measurements revealing a 2 meV gap with quantized edge conductance, indicating a topological excitonic insulator phase.
Article Abstract
Electron-hole pairing can occur in a dilute semimetal, transforming the system into an excitonic insulator state in which a gap spontaneously appears at the Fermi surface, analogous to a Bardeen-Cooper-Schrieffer (BCS) superconductor. Here, we report optical spectroscopic and electronic transport evidence for the formation of an excitonic insulator gap in an inverted InAs/GaSb quantum-well system at low temperatures and low electron-hole densities. Terahertz transmission spectra exhibit two absorption lines that are quantitatively consistent with predictions from the pair-breaking excitation dispersion calculated based on the BCS gap equation. Low-temperature electronic transport measurements reveal a gap of ~2 meV (or ~25 K) with a critical temperature of ~10 K in the bulk, together with quantized edge conductance, suggesting the occurrence of a topological excitonic insulator phase.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5719361 | PMC |
| http://dx.doi.org/10.1038/s41467-017-01988-1 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Want 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!