Research - Tsymbal Group

Our research is broadly focused on using first-principles calculations and model approaches to predict novel electronic, magnetic, ferroelectric, and transport properties of materials and structures that are interesting from the point of view of new functionalities. We are collaborating with a number of experimental groups at the University of Nebraska and other institutions to correlate our predictions with experimental studies and explore new systems in practice.

 

Current research areas:

(i) interface magnetoelectric effects
(ii) ferroelectric and multiferroic tunnel junctions
(iii) two-dimensional electron gases (2DEGs) at oxide interfaces
(iv) spin-dependent tunneling
(v) magnetic nanocontacts and nanowires  
(vi) interlayer exchange and magnetostatic coupling  
(vii) oxide heterostructures
Interface Magnetoelectric Effects

Interface Magnetoelectric Effects

The control of magnetic properties of materials via the application of electric field, known as magneto-electric coupling, is among the most fascinating and active materials research areas today. There are several known mechanisms responsible for magnetoelectric coupling including intrinsic effects in single-phase materials, strain induced coupling in two-phase composites, and electronically-driven interface magnetoelectric effects. More ...

Ferroelectric Tunnel Junctions

Ferroelectric Tunnel Junctions

Ferroelectric thin films are promising for applications in data storage and nanoelectronics due to their spontaneous electric polarization that can be switched by an applied electric field. Recent experimental and theoretical findings suggest that ferroelectricity persists down to a nanometer scale, which opens a possibility to use ferroelectric thin films as tunnel barriers in ferroelectric tunnel junctions (FTJ's).
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2DEGs at Oxide Interfaces

2DEGs at Oxide Interfaces

The discovery of a two dimensional electron gas (2DEG) at the interface between two insulating oxides LaAlO3 and SrTiO3 has attracted significant interest due to possible applications in all-oxide electronic devices. Stimulated by this discovery density-functional calculations are performed to understand properties of 2DEG and explore new functionalities.
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Spin-Dependent Tunneling

Spin-Dependent Tunneling

Spin-dependent tunneling (SDT) is an imbalance in the electric current carried by up- and down-spin electrons tunneling from a ferromagnet through an insulating barrier.  A related phenomenon is tunneling magnetoresistance (TMR) that is a change in the resistance of a magnetic tunnel junction (MTJ) when the magnetization of the two ferromagnetic layers changes its alignment. More ...

Magnetic Nanocontacts

Magnetic Nanocontacts

When the dimensions of a metallic conductor are reduced so that they become comparable to the de Broglie wavelengths of the conduction electrons, the conductance becomes quantized. In ferromagnetic metals, the exchange splitting of spin bands leads to spin-dependent conductance quantization and various unusual magnetoresistive phenomena. More ...

Interlayer Coupling

Interlayer Coupling

Interlayer coupling in magnetic thin-film layered structures play an important role in controlling their magnetic properties. The coupling may originate from exchange and magnetostatic interactions affecting magnetizations of ferromagnetic films across a non-magnetic spacer layer. For a metallic spacer the interlayer exchange coupling oscillates as a function of its thickness. More ...