Microscopic Structure of the Metal-Insulator Transition in Two Dimensions
Abstract
A single electron transistor is used as a local electrostatic probe to study the underlying spatial structure of the metal-insulator transition in two dimensions. The measurements show that as we approach the transition from the metallic side, a new phase emerges that consists of weakly coupled fragments of the two-dimensional system. These fragments consist of localized charge that coexists with the surrounding metallic phase. As the density is lowered into the insulating phase, the number of fragments increases on account of the disappearing metallic phase. The measurements reveal that the metal-insulator transition is a result of the microscopic restructuring that occurs in the system.
Get full access to this article
View all available purchase options and get full access to this article.
Already a Subscriber?Sign In
REFERENCES AND NOTES
1
Abrahams E., Anderson P. W., Licciardello D. C., Ramakrishnan T. V., Phys. Rev. Lett. 42, 673 (1979).
2
S. V. Kravchenko, G. V. Kravchenko, J. E. Furneaux, V. M. Pudalov, M. D'Iorio, Phys. Rev. B Cond. Matter 50, 8039 (1994).
3
For a comprehensive review of the MIT in 2D, see
Abrahams E., Kravchenko S. V., Sarachik M. P., Rev. Mod. Phys. 73, 251 (2001).
4
Ilani S., Yacoby A., Mahalu D., Shtrikman H., Phys. Rev. Lett. 84, 3133 (2000).
5
Y. Hanein et al., Phys. Rev. Lett.80, 1288 (1998).
6
M. J. Yoo et al., Science276, 579 (1997).
7
Wei Y. Y., Weis J., Klitzing K. V., Eberl K., Phys. Rev. Lett. 81, 1674 (1998).
8
N. B. Zhitenev et al., Nature404, 473 (2000).
9
Eisenstein J. P., Pfeiffer L. N., West K. W., Phys. Rev. Lett. 68, 674 (1992).
10
S. Shapira et al., Phys. Rev. Lett.77, 3181 (1996).
11
The critical density was determined by simultaneous measurement on the same device, with the same technique as in (4).
12
Dultz S. C., Jiang H. W., Phys. Rev. Lett. 84, 4689 (2000).
13
A possible explanation of this behavior, which relates it to effects of disorder, has been given by Si and Varma [
Si Q., Varma C. M., Phys. Rev. Lett. 81, 4951 (1998)].
14
B. L. Altshuler, D. L. Maslov, V. P. Pudalov, preprint available at xxx.lanl.gov/abs/cond-mat0003032.
15
Efros A. L., Shklovskii B. I., J. Phys. C Solid State Phys. 8, L49 (1975).
16
He S., Xie X. C., Phys. Rev. Lett. 80, 3324 (1998).
17
Meir Y., Phys. Rev. Lett. 83, 3506 (1999).
18
An electron crystal, which is suggested by several theories (19–23) to appear at the MIT, might produce both continuos and discrete behaviors. Generally, the crystal deforms continuously to screen an external potential, producing a continuous response. However, occasionally, electrons collectively reorganize around pinning centers (24), causing an abrupt reduction of energy and hence a spike in δμ/δVBG. In this scenario, a single spike corresponds to a many-electron charging event, rather than a single-electron charging, as in previous scenarios.
19
Tanatar B., Ceperley D. M., Phys. Rev. B 39, 5005 (1989).
20
Chui S. T., Tanatar B., Phys. Rev. Lett. 74, 458 (1995).
21
Benenti G., Xavier W., Pichard J. L., Phys. Rev. Lett. 83, 1826 (1999).
22
Chakravarty S., Kivelson S., Nayak C., Voelker K., Philos. Mag. B 79, 859 (1999).
23
Yoon J., Li C. C., Shahar D., Tsui D. C., Shayegan M., Phys. Rev. Lett. 82, 1744 (1999).
24
Ruzin I. M., Marianer S., Shklovskii B. I., Phys. Rev. B Cond. Matter 46, 3999 (1992).
25
The value of smin could be estimated from the ratio of capacitances between the 2DHG and the top and back gates to be smin = 2.3.
26
M. Pollak, M. Ortuno, in Electron-Electron Interactions In Disordered Systems, A. L. Efros, M. Pollak, Eds. (North-Holland, Amsterdam, 1985), vol. 10, pp. 287–408.
27
We benefited from discussions with M. Brodsky, A. M. Finkel'stein, Y. Imry, Y. Meir, A. Stern, C. M. Varma, and N. B. Zhitenev. This work was supported by the MINERVA Foundation, Germany.
Information & Authors
Information
Published In
Science
Volume 292 | Issue 5520
18 May 2001
18 May 2001
Submission history
Received: 27 December 2000
Accepted: 4 April 2001
Published in print: 18 May 2001
Authors
Metrics & Citations
Metrics
Article Usage
Altmetrics
Citations
Export citation
Select the format you want to export the citation of this publication.
Cited by
- Long-Range Order in Electronic Transport Through Disordered Metal Films, Science, 319, 5867, (1226-1229), (2021)./doi/10.1126/science.1152458
- Metal-Insulator Transition in Disordered Two-Dimensional Electron Systems, Science, 310, 5746, (289-291), (2021)./doi/10.1126/science.1115660
- Localization of Fractionally Charged Quasi-Particles, Science, 305, 5686, (980-983), (2021)./doi/10.1126/science.1099950
Loading...
View Options
Get Access
Log in to view the full text
AAAS login provides access to Science for AAAS Members, and access to other journals in the Science family to users who have purchased individual subscriptions.
- Become a AAAS Member
- Activate your AAAS ID
- Purchase Access to Other Journals in the Science Family
- Account Help
Log in via OpenAthens.
Log in via Shibboleth.
More options
Purchase digital access to this article
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
View options
PDF format
Download this article as a PDF file
Download PDF