Electronic transport in thin films of BaPbO3 : Unraveling two-dimensional quantum effects

Abstract

Recently, perovskite related BaPbO3 has attracted attention due to its hidden topological properties and, moreover, has been used as a thin layer in heterostructures to induce two-dimensional superconductivity. Here we investigate the normal state electronic transport properties of thin films of BaPbO3. Temperature and magnetic field dependent sheet resistances are strongly affected by two-dimensional quantum effects. Our analysis decodes the interplay of spin-orbit coupling, disorder, and electron-electron interaction in this compound. Similar to recently discussed topological materials, we find that weak antilocalization is the dominant protagonist in magnetotransport, whereas electron-electron interactions play a pronounced role in the temperature dependence. A systematic understanding of these quantum effects is essential to allow for an accurate control of properties not only of thin films of BaPbO3, but also of topological heterostructures.

Magnetotransport of Functional Oxide Heterostructures Affected by Spin-Orbit Coupling: A Tale of Two-Dimensional Systems

“…Figure 1 summarizes temperature-dependent MR data taken from a 15.0 nm thick BaPbO 3 thin lm showing an increase in MR to a maximum value at a magnetic eld of ≈ 0.85 T with a following decrease at higher magnetic elds, con rming our former results. [8] The MR data were corrected from concomitant EEI by subtracting its contribution via Equation (II.11) with = 0.906 retrieved from □ ( ) analysis. As expected, EEI contributes only slightly (see colored lines in Figure 1).…”

“…For consistency, we applied the just established self-consistent calculations of so and to the data presented in [8] comparing di erent sample thicknesses: For the sample with thickness 21.3 nm the WAL contribution expressed by so changes from 0.11 T to 0.127 T, whereas EEI represented by increases slightly from 0.97 to 0.974. The 4.8 nm thick sample shows a small increase of so from 0.24 T to 0.243 T, whereas changes from 0.84 to 0.887.…”

“…Recently we found that BaPbO 3 thin lms grown on (001) oriented SrTiO 3 single crystals show single-band behavior and a pronounced magnetoresistance (MR) which at low magnetic elds is evidently ruled by WAL. [8] Surprisingly, temperaturedependent measurements of the sheet resistance □ ( ) account for an insulating low-temperature state, contradicting the WAL result of magnetoconductance. Such a counterintuitive behavior of thin lm samples was observed before.…”

Magnetotransport of Functional Oxide Heterostructures Affected by Spin–Orbit Coupling: A Tale of Two‐Dimensional Systems

“…Figure 1 shows temperature‐dependent data taken from a 15.0 nm‐thick BaPbO 3 thin film showing an increase in to a maximum value at a magnetic field of with a following decrease at higher magnetic fields, confirming our former results. [ 8 ] The MR data were corrected from concomitant EEI by subtracting its contribution via Equation (11) with retrieved from analysis. As expected, EEI contributes only slightly (see colored lines in Figure 1).…”

“…Recently, we found that BaPbO 3 thin films grown on (001)‐oriented SrTiO 3 single crystals show single‐band behavior and a pronounced magnetoresistance (MR) which at low magnetic fields is evidently ruled by WAL. [ 8 ] Surprisingly, temperature‐dependent measurements of the sheet resistance account for an insulating low‐temperature state, contradicting the WAL result of magnetoconductance. Such a counterintuitive behavior of thin film samples was observed before.…”