| Title: |
Evidence for an excitonic insulator phase in a zero-gap InAs/GaSb bilayer |
| Authors: |
Yu, W., Clericò, V., Fuentevilla, C. Hernández, Shi, X., Jiang, Y., Saha, D., Lou, W. K., Chang, K., Huang, D. H., Gumbs, G., Smirnov, D., Stanton, C. J., Jiang, Z., Bellani, V., Meziani, Y., Diez, E., Pan, W., Hawkins, S. D., Klem, J. F. |
| Publication Year: |
2017 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Materials Science |
| More Details: |
Many-body interactions can produce novel ground states in a condensed-matter system. For example, interacting electrons and holes can spontaneously form excitons, a neutral bound state, provided that the exciton binding energy exceeds the energy separation between the single particle states. Here we report on electrical transport measurements on spatially separated two-dimensional electron and hole gases with nominally degenerate energy subbands, realized in an InAs(10 nm)/GaSb(5 nm) coupled quantum well. We observe a narrow and intense maximum (~500 k\Omega) in the four-terminal resistivity in the charge neutrality region, separating the electron-like and hole-like regimes, with a strong activated temperature-dependence above T = 7 K and perfect stability against quantizing magnetic fields. By quantitatively comparing our data with early theoretical predictions, we show that such unexpectedly large resistance in our nominally zero-gap semi-metal system is probably due to the formation of an excitonic insulator state. |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/1701.07417 |
| Accession Number: |
edsarx.1701.07417 |
| Database: |
arXiv |
