Modulation-doping a correlated electron insulator
Abstract
Correlated electron materials (CEMs) host a rich variety of condensed matter phases. Vanadium dioxide (VO2) is a prototypical CEM with a temperature-dependent metal-to-insulator (MIT) transition with a concomitant crystal symmetry change. External control of MIT in VO2—especially without inducing structural changes—has been a long-standing challenge. In this work, we design and synthesize modulation-doped VO2-based thin film heterostructures that closely emulate a textbook example of filling control in a correlated electron insulator. Using a combination of charge transport, hard X-ray photoelectron spectroscopy, and structural characterization, we show that the insulating state can be doped to achieve carrier densities greater than 5 × 1021 cm−3 without inducing any measurable structural changes. We find that the MIT temperature (TMIT) continuously decreases with increasing carrier concentration. Remarkably, the insulating state is robust even at doping concentrations as high as ~0.2 e−/vanadium. Finally, our work reveals modulation-doping as a viable method for electronic control of phase transitions in correlated electron oxides with the potential for use in future devices based on electric-field controlled phase transitions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 05, 2023
- Source ID
- 10.1038/s41467-023-41816-3
Entities
People
- A. X. Gray
- Abigail M. Derrico
- Andrei Gloskovskii
- Atsushi Hariki
- Awadhesh Narayan
- Christoph Schlueter
- Debasish Mondal
- Dipankar Das Sarma
- Frank M F de Groot
- Jay R. Paudel
- Nagaphani Aetukuri
- Pavan Nukala
- Rajdeep Banerjee
- Rajeev Kumar Rai
- Smruti Rekha Mahapatra
Organizations
- Alexander von Humboldt Foundation
- Army Research Office
- Department of Science and Technology
- Indian Institute of Science, Bengaluru
- Japan Society for the Promotion of Science
- Ministry of Education
- United States Department of Energy
- University Grants Commission