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.
| Original language | English |
|---|---|
| Article number | 6210 |
| Pages (from-to) | 1-11 |
| Journal | Nature Communications |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 5 Oct 2023 |
Bibliographical note
Publisher Copyright:© 2023, Springer Nature Limited.
Funding
A.X.G., A.M.D., and J.R.P. acknowledge support from the DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences, and Engineering Division under Award No. DE-SC0019297. The electrostatic photoelectron analyzer for the lab-based HAXPES measurements at Temple University was acquired through an Army Research Office DURIP grant (Grant No. W911NF-18-1-0251). We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime at DESY was allocated for proposal I-20210142. Funding for the HAXPES instrument at beamline P22 by the Federal Ministry of Education and Research (BMBF) under the framework program ErUM is gratefully acknowledged. A.X.G. also gratefully acknowledges the support from the Alexander von Humboldt Foundation. P.N. and R.K.R. acknowledge the Advanced Facility for Microscopy and Microanalysis (AFMM) for providing the electron microscope and FIB facility. A.N. acknowledges support from the startup grant at the Indian Institute of Science (SG/MHRD-19-0001). The authors acknowledge the micro nano characterization facility, national nanofabrication center, and the packaging lab at CeNSE, IISc for access to HR-XRD, wire bonding, and clean-room facilities. N.B.A. acknowledges the new faculty startup grant provided by the Indian Institute of Science under Grant No. 12-0205-0618-77. N.B.A. is thankful to Professor Anil Kumar for access to the PLD system. S.R.M. and D.M. want to thank Jibin J. Samuel and Mithun Ghosh for useful discussions. We thank Professor Satish Patil for providing access to facilities supported by the Swarnajayanti fellowship under Grant No. DST/SJF/CSA-01/2013-14. AFM measurements were performed on a Cypher-ES AFM funded by the DST-FIST program and Hall measurements were performed on a PPMS-Dynacool system funded under the UGC-CAS program. A.H. was supported by JSPS KAKENHI Grant Numbers 21K13884, 21H01003, 23H03816, 23H03817, and the 2023 Osaka Metropolitan University (OMU) Strategic Research Promotion Project for Younger Researcher. D.D.S. thanks Council of Scientific and Industrial Research for support. A.X.G., A.M.D., and J.R.P. acknowledge support from the DOE, Office of Science, Office of Basic Energy Sciences, Materials Sciences, and Engineering Division under Award No. DE-SC0019297. The electrostatic photoelectron analyzer for the lab-based HAXPES measurements at Temple University was acquired through an Army Research Office DURIP grant (Grant No. W911NF-18-1-0251). We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime at DESY was allocated for proposal I-20210142. Funding for the HAXPES instrument at beamline P22 by the Federal Ministry of Education and Research (BMBF) under the framework program ErUM is gratefully acknowledged. A.X.G. also gratefully acknowledges the support from the Alexander von Humboldt Foundation. P.N. and R.K.R. acknowledge the Advanced Facility for Microscopy and Microanalysis (AFMM) for providing the electron microscope and FIB facility. A.N. acknowledges support from the startup grant at the Indian Institute of Science (SG/MHRD-19-0001). The authors acknowledge the micro nano characterization facility, national nanofabrication center, and the packaging lab at CeNSE, IISc for access to HR-XRD, wire bonding, and clean-room facilities. N.B.A. acknowledges the new faculty startup grant provided by the Indian Institute of Science under Grant No. 12-0205-0618-77. N.B.A. is thankful to Professor Anil Kumar for access to the PLD system. S.R.M. and D.M. want to thank Jibin J. Samuel and Mithun Ghosh for useful discussions. We thank Professor Satish Patil for providing access to facilities supported by the Swarnajayanti fellowship under Grant No. DST/SJF/CSA-01/2013-14. AFM measurements were performed on a Cypher-ES AFM funded by the DST-FIST program and Hall measurements were performed on a PPMS-Dynacool system funded under the UGC-CAS program. A.H. was supported by JSPS KAKENHI Grant Numbers 21K13884, 21H01003, 23H03816, 23H03817, and the 2023 Osaka Metropolitan University (OMU) Strategic Research Promotion Project for Younger Researcher. D.D.S. thanks Council of Scientific and Industrial Research for support.
| Funders | Funder number |
|---|---|
| Center for Environmental and Sustainability Research (CENSE) | |
| Osaka Metropolitan University | |
| U.S. Department of Energy | |
| Alexander von Humboldt Stiftung | |
| Office of Science | |
| Basic Energy Sciences | |
| Indian Institute of Science Bangalore | 12-0205-0618-77, SG/MHRD-19-0001, DST/SJF/CSA-01/2013-14 |
| Division of Materials Sciences and Engineering | DE-SC0019297, W911NF-18-1-0251 |
| Department of Science and Technology, Ministry of Science and Technology, India | |
| Council of Scientific and Industrial Research, India | |
| University Grants Commission | |
| Japan Society for the Promotion of Science | 23H03816, 21K13884, 23H03817, 21H01003 |
| Bundesministerium für Bildung und Forschung | |
| Max Delbrück Center for Molecular Medicine in the Helmholtz Association | I-20210142 |