In-plane anisotropy in two-dimensional electron gas at LaAlO ₃ /SrTiO ₃ (110) interface

Abstract

A systematic study of the two-dimensional electron gas at LaAlO 3 /SrTiO 3 (110) interface reveals an anisotropy along two specific directions, [001] and 1 10 . The anisotropy becomes distinct for the interface prepared under high oxygen pressure with low carrier density. Angular dependence of magnetoresistance shows that the electron confinement is stronger along the 1 10 direction. Gate-tunable magnetoresistance reveals a clear in-plane anisotropy of the spin-orbit coupling, and the spin relaxation mechanism along both directions belongs to D'yakonov-Perel' (DP) scenario. Moreover, in-plane anisotropic superconductivity is observed for the sample with high carrier density, the superconducting transition temperature is lower but the upper critical field is higher along the 1 10 direction. This in-plane anisotropy could be ascribed to the anisotropic band structure along the two crystallographic directions.

Nature of electrons from oxygen vacancies and polar catastrophe at LaAlO3/SrTiO3 interfaces

“…However, the magnetotransport studies performed by Caviglia et al [17] and other studies [18][19][20][21][22][23] suggested that instead of magnetic scattering, the lowtemperature electron scattering at the LAO/STO interface was dominated by quantum conductivity correction due to the constructive interference between time-reversed electron paths, i.e., weak localization. Up to now, low-temperature electron scattering mechanism for electrons at the LAO/STO interface has been controversial [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. One important aspect on this divergence could be that the origin of electrons at the LAO/STO interfaces can be different from group to group depending on the fabrication conditions.…”

“…Many studies also used the Kondo effect to explain the low-temperature electron scattering for LAO/STO [11][12][13][14][15][16]. However, the magnetotransport studies performed by Caviglia et al [17] and other studies [18][19][20][21][22][23] suggested that instead of magnetic scattering, the lowtemperature electron scattering at the LAO/STO interface was dominated by quantum conductivity correction due to the constructive interference between time-reversed electron paths, i.e., weak localization. Up to now, low-temperature electron scattering mechanism for electrons at the LAO/STO interface has been controversial [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

Gate tunable Rashba spin-orbit coupling at CaZrO3/SrTiO3 heterointerface

“…Owing to the rapid development of film technology, a large amount of oxide heterointerfaces among transition metal oxides (TMOs) have been fabricated intensively, exhibiting a lot of intriguing physical functionalities because of their unique electronic structure and properties. [1][2][3][4][5][6][7][8][9][10] One typical breakthrough was that the interface between two ABO 3 type perovskite insulators, e.g., LaAlO 3 and SrTiO 3 (LAO/STO), hosts a high-mobility two-dimensional electron gas (2DEG). [11] The conductive interface possesses quantities of fascinating properties such as ferromagnetism, [12][13][14] superconductivity, [15,16] and strong Rashba spin-orbit coupling (Rashba-SOC), [17] which results from the interfacial breaking of inversion symmetry.…”

Ferroelectric Metal in Tetragonal BiCoO3/BiFeO3 Bilayers and Its Electric Field Effect

“…Besides, compounding BFO with BCO is accessible experimentally in the form of epitaxial thin film 40 and the BFO/BCO multiferroic solid solutions are studied theoretically 41 . Previous studies show that the antiferromagnetic insulator BiFeO 3 can exhibit ferromagnetism in BiFeO 3 /La 2/3 Sr 1/3 MnO 3 interface 42 43 and two-dimensional electron gas in BiFeO 3 /SrTiO 3 interface 44 , demonstrating that heterointerface is significant in BiFeO 3 -based bilayers. However, the heterostructures by constructing BiFeO 3 with another multiferroic BiCoO 3 may present some fantastic properties based on its multiferroic characteristics.…”