Locally enhanced conductivity due to the tetragonal domain structure in LaAlO3/SrTiO3 heterointerfaces
Source abstract
Abstract
The ability to control materials properties through interface engineering is demonstrated by the appearance of conductivity at the interface of certain insulators, most famously the {001} interface of the band insulators LaAlO3 and TiO2-terminated SrTiO3 (STO; refs 1, 2). Transport and other measurements in this system show a plethora of diverse physical phenomena. To better understand the interface conductivity, we used scanning superconducting quantum interference device microscopy to image the magnetic field locally generated by current in an interface. At low temperature, we found that the current flowed in conductive narrow paths oriented along the crystallographic axes, embedded in a less conductive background. The configuration of these paths changed on thermal cycling above the STO cubic-to-tetragonal structural transition temperature, implying that the local conductivity is strongly modified by the STO tetragonal domain structure. The interplay between substrate domains and the interface provides an additional mechanism for understanding and controlling the behaviour of heterostructures.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Electronic and Structural Properties of Oxides · Magnetic and transport properties of perovskites and related materials · Ferroelectric and Negative Capacitance Devices
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (37)
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1. Ohtomo, A. & Hwang, H. Y. A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface. Nature 427, 423–426 (2004).10.1038/nature02308 ↗
2. Nakagawa, N., Hwang, H. Y. & Muller, D. A. Why some interfaces cannot be sharp. Nature Mater. 5, 204–209 (2006).10.1038/nmat1569 ↗
3. Thiel, S., Hammerl, G., Schmehl, A., Schneider, C. W. & Mannhart, J. Tunable quasi-two-dimensional electron gases in oxide heterostructures. Science 313, 1942–1945 (2006).10.1126/science.1131091 ↗
4. Reyren, N. et al. Superconducting interfaces between insulating oxides. Science 317, 1196–1199 (2007).10.1126/science.1146006 ↗
5. Brinkman, A. et al. Magnetic effects at the interface between non-magnetic oxides. Nature Mater. 6, 493–496 (2007).10.1038/nmat1931 ↗
6. Caviglia, A. D. et al. Electric field control of the LaAlO3/SrTiO3 interface ground state. Nature 456, 624–627 (2008).10.1038/nature07576 ↗
7. Bell, C. et al. Dominant mobility modulation by the electric field effect at the LaAlO3/SrTiO3 interface. Phys. Rev. Lett. 103, 226802 (2009).10.1103/PhysRevLett.103.226802 ↗
8. Seri, S. & Klein, L. Antisymmetric magnetoresistance of the SrTiO3/LaAlO3 interface. Phys. Rev. B 80, 180410 (2009).10.1103/PhysRevB.80.180410 ↗
9. Ben Shalom, M., Ron, A., Palevski, A. & Dagan, Y. Shubnikov De Haas oscillations in SrTiO3/LaAlO3 interface. Phys. Rev. Lett. 105, 206401 (2010).10.1103/PhysRevLett.105.206401 ↗
10. Ariando, et al. Electronic phase separation at the LaAlO3/SrTiO3 interface. Nature Commun. 2, 188 (2010).10.1038/ncomms1192 ↗
11. Dikin, D. A. et al. Coexistence of superconductivity and ferromagnetism in two dimensions. Phys. Rev. Lett. 107, 056802 (2011).10.1103/PhysRevLett.107.056802 ↗
12. Li, L., Richter, C., Mannhart, J. & Ashoori, R. C. Coexistence of magnetic order and two-dimensional superconductivity at LaAlO3/SrTiO3 interfaces. Nature Phys. 7, 762–766 (2011).10.1038/nphys2080 ↗
13. Bert, J. A. et al. Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface. Nature Phys. 7, 767–771 (2011).10.1038/nphys2079 ↗
14. Kalisky, B. et al. Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures. Nature Commun. 3, 922 (2012).10.1038/ncomms1931 ↗
15. Mannhart, J. & Schlom, D. G. Oxide interfaces—An opportunity for electronics. Science 327, 1607–1611 (2010).10.1126/science.1181862 ↗
16. Cancellieri, C. et al. Electrostriction at the LaAlO3/SrTiO3 interface. Phys. Rev. Lett. 107, 056102 (2011).10.1103/PhysRevLett.107.056102 ↗
17. Ben Shalom, M., Sachs, M., Rakhmilevitch, D., Palevski, A. & Dagan, Y. Tuning spin-orbit coupling and superconductivity at the SrTiO3/LaAlO3 interface: A magnetotransport study. Phys. Rev. Lett. 104, 126802 (2010).10.1103/PhysRevLett.104.126802 ↗
18. Joshua, A., Ruhman, J., Pecker, S., Altman, E. & Ilani, S. Gate-tunable polarized phase of two-dimensional electrons at the LaAlO3/SrTiO3 interface. Proc. Natl Acad. Sci. USA 110, 9633–9638 (2012).10.1073/pnas.1221453110 ↗
19. Caviglia, A. D. et al. Tunable Rashba spin-orbit interaction at oxide interfaces. Phys. Rev. Lett. 104, 126803 (2010).10.1103/PhysRevLett.104.126803 ↗
20. Fête, A., Gariglio, S., Caviglia, A. D., Triscone, J. M. & Gabay, M. Rashba induced magnetoconductance oscillations in the LaAlO3−SrTiO3 heterostructure. Phys. Rev. B 86, 201105 (2012).10.1103/PhysRevB.86.201105 ↗
21. Gardner, B. W. et al. Scanning superconducting quantum interference device susceptometry. Rev. Sci. Instrum. 72, 2361–2364 (2001).10.1063/1.1364668 ↗
22. Huber, M. E. et al. Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples. Rev. Sci. Instrum. 79, 053704 (2008).10.1063/1.2932341 ↗
23. Nowack, K. C. et al. Imaging currents in HgTe quantum wells in the quantum spin Hall regime. Nature Mater. advance online publication (2013).10.1038/nmat3682 ↗
24. Bert, J. A. et al. Gate-tuned superfluid density at the superconducting LaAlO3/SrTiO3 interface. Phys. Rev. B 86, 060503 (2012).10.1103/PhysRevB.86.060503 ↗
25. Bristowe, N. C., Fix, T., Blamire, M. G., Littlewood, P. B. & Artacho, E. Proposal of a one-dimensional electron gas in the steps at the LaAlO3–SrTiO3 interface. Phys. Rev. Lett. 108, 166802 (2012).10.1103/PhysRevLett.108.166802 ↗
26. Cowley, R. A. Lattice dynamics and phase transitions of strontium titanate. Phys. Rev. 134, A981–A997 (1964).10.1103/PhysRev.134.A981 ↗
27. Unoki, H. & Sakudo, T. Electron spin resonance of Fe3+ in SrTiO3 with special reference to the 110°K phase transition. J. Phys. Soc. Jpn 23, 546–552 (1967).10.1143/JPSJ.23.546 ↗
28. Cao, W. & Barsch, G. R. Landau–Ginzburg model of interphase boundaries in improper ferroelastic perovskites of D4h18 symmetry. Phys. Rev. B 41, 4334–4348 (1990).10.1103/PhysRevB.41.4334 ↗
29. Schwingenschlögl, U. & Schuster, C. Interface relaxation and electrostatic charge depletion in the oxide heterostructure LaAlO3/SrTiO3 . Europhys. Lett. 86, 27005 (2009).10.1209/0295-5075/86/27005 ↗
30. Pauli, S. A. et al. Evolution of the interfacial structure of LaAlO3 on SrTiO3 . Phys. Rev. Lett. 106, 036101 (2011).10.1103/PhysRevLett.106.036101 ↗
31. Jia, C. L. et al. Oxygen octahedron reconstruction in the SrTiO3/LaAlO3 heterointerfaces investigated using aberration-corrected ultrahigh-resolution transmission electron microscopy. Phys. Rev. B 79, 081405 (2009).10.1103/PhysRevB.79.081405 ↗
32. Stengel, M. First-principles modeling of electrostatically doped perovskite systems. Phys. Rev. Lett. 106, 136803 (2011).10.1103/PhysRevLett.106.136803 ↗
33. Seidel, J. et al. Conduction at domain walls in oxide multiferroics. Nature Mater. 8, 229–234 (2009).10.1038/nmat2373 ↗
34. Guyonnet, J., Gaponenko, I., Gariglio, S. & Paruch, P. Conduction at domain walls in insulating Pb(Zr0.2Ti0.8)O3 thin films. Adv. Mater. 23, 5377–5382 (2011).10.1002/adma.201102254 ↗
35. Scott, J. F., Salje, E. K. H. & Carpenter, M. A. Domain wall damping and elastic softening in SrTiO3: Evidence for polar twin walls. Phys. Rev. Lett. 109, 187601 (2012).10.1103/PhysRevLett.109.187601 ↗
36. Morozovska, A. N. et al. Impact of free charges on polarization and pyroelectricity in antiferrodistortive structures and surfaces induced by a flexoelectric effect. Ferroelectrics 438, 32–44 (2012).10.1080/00150193.2012.744257 ↗
37. Jalan, B., Allen, S. J., Beltz, G. E., Moetakef, P. & Stemmer, S. Enhancing the electron mobility of SrTiO3 with strain. Appl. Phys. Lett. 98, 132102–132103 (2011).10.1063/1.3571447 ↗