Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userLow-temperature dependence of the thermo-magnetic transport properties of the SrTiO3/LaAlO3 interface
249
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We report transport measurements, including: Hall, Seebeck and Nernst Effect. All these transport properties exhibit anomalous field and temperature dependences, with a change of behavior observed at about H 1.5T and T 15K. We were able to reconcile the low-temperature-low-field behavior of all transport properties using a simple two band analysis. A more detailed model is required in order to explain the high magnetic field regime.
rate research
Read More
Here we investigate LaAlO_3-SrTiO_3 heterostructure withdelta-doping of the interface by LaMnO_3 at less than one monolayer. This doping strongly inhibits the formation of mobile electron layer at the interface. This results in giant increase of the resistance and the thermopower of the heterostructure. Several aspects of this phenomena are investigated. A model to calculate the carrier concentration is presented and effect of doping and detailed temperature dependence is analyzed in terms of model parameters and the weak-scattering theory. The large enhancement of thermopower is attributed to the increased spin and orbital entropy originating from the LaMnO_3 mono-layer.
We present low-temperature and high-field magnetotransport data on SrTiO3-LaAlO3 interfaces. The resistance shows hysteresis in magnetic field and a logarithmic relaxation as a function of time. Oscillations in the magnetoresistance are observed, showing a square root periodicity in the applied magnetic field, both in large-area unstructured samples as well as in a structured sample. An explanation in terms of a commensurability condition of edge states in a highly mobile two-dimensional electron gas between substrate step edges is suggested.
The interface between the two band insulators SrTiO3 and LaAlO3 unexpectedly has the properties of a two dimensional electron gas. It is even superconducting with a transition temperature, Tc, that can be tuned using gate bias Vg, which controls the number of electrons added or removed from the interface. The gate bias - temperature (Vg, T) phase diagram is characterized by a dome-shaped region where superconductivity occurs, i.e., Tc has a non-monotonic dependence on Vg, similar to many unconventional superconductors. In this communication the frequency of the quantum resistance-oscillations versus inverse magnetic field is reported for various Vg. This frequency follows the same nonmonotonic behavior as Tc; similar trend is seen in the low field limit of the Hall coefficient. We theoretically show that electronic correlations result in a non-monotonic population of the mobile band, which can account for the experimental behavior of the normal transport properties and the superconducting dome.
The magnetoresistance as a function of temperature and field for atomically flat interfaces between 8 unit cells of LaAlO3 and SrTiO3 is reported. Anomalous anisotropic behavior of the magnetoresistance is observed below 30 K for superconducting samples with carrier concentration of 3.5times10^13 cm^-2 . We associate this behavior to a magnetic order formed at the interface.
A d-orbital electron has an anisotropic electron orbital and is a source of magnetism. The realization of a 2-dimensional electron gas (2DEG) embedded at a LaAlO3/SrTiO3 interface surprised researchers in materials and physical sciences because the 2DEG consists of 3d-electrons of Ti with extraordinarily large carrier mobility, even in the insulating oxide heterostructure. To date, a wide variety of physical phenomena, such as ferromagnetism and the quantum Hall effect, have been discovered in this 2DEG systems, demonstrating the ability of the d-electron 2DEG systems to provide a material platform for the study of interesting physics. However, because of both ferromagnetism and the Rashba field, long-range spin transport and the exploitation of spintronics functions have been believed difficult to implement in the d-electron 2DEG systems. Here, we report the experimental demonstration of room-temperature spin transport in the d-electron-based 2DEG at a LaAlO3/SrTiO3 interface, where the spin relaxation length is ca. exceeding 200 nm. Our finding, which counters the conventional understandings to d-electron 2DEGs, opens a new field of d-electron spintronics. Furthermore, this work highlights a novel spin function in the conductive oxide system.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
