Correlation between superconductivity, band filling, and electron confinement at the LaAlO3/SrTiO3 interface
| Autor: | W.G. van der Wiel, Hans Hilgenkamp, M.P. Stehno, Alexander Brinkman, A. E. M. Smink, J. C. De Boer |
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| Rok vydání: | 2018 |
| Předmět: |
Superconductivity
Physics Condensed matter physics 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Gate voltage 01 natural sciences 0103 physical sciences Superconducting critical temperature Laalo3 srtio3 010306 general physics 0210 nano-technology Electron confinement Phase diagram Surface states Relative energy |
| Zdroj: | Physical Review B. 97 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | By combined top- and backgating, we explore the correlation of superconductivity with band filling and electron confinement at the ${\mathrm{LaAlO}}_{3}\text{/}{\mathrm{SrTiO}}_{3}$ interface. We find that the top- and backgate voltages have distinctly different effects on the superconducting critical temperature, implying that the confining potential well has a profound effect on superconductivity. We investigate the origin of this behavior by comparing the gate dependence of ${T}_{c}$ to the corresponding evolution of the band filling with gate voltage. For several backgate voltages, we observe maximum ${T}_{c}$ to consistently coincide with a kink in tuning the band filling for high topgate voltage. Self-consistent Schr\"odinger-Poisson calculations relate this kink to a Lifshitz transition of the second ${d}_{xy}$ subband. These results establish a major role for confinement-induced subbands in the phase diagram of ${\mathrm{SrTiO}}_{3}$ surface states, and establish gating as a means to control the relative energy of these states. |
| Databáze: | OpenAIRE |
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