Spintronics

Spintronics is an emerging technology in which the spin degrees of freedom of the electron play a fundamental role, in contrast to the charge degrees of freedom in conventional electronic devices.

Our research is focused on the control and the use of spin degrees of freedom, on fundamentals of the development of spin electronic devices and on the possibility of injecting spin polarised currents. The well known Rashba effect plays a central role in this research. Together with Halperin (Harvard) and Efros (Naval Research Lab), Rashba has developed the theory of spin generation by nonlinear transport, of spin Hall conductivity and of the electric dipole resonance (Rashba resonance) in quantum dots. This has led to studies of networks of small magnetic particles, nanomagnets and nano-mechanical systems. Experimental work on thin and ultra-thin films and heterostructures such as Co₂MnSi deposited in house by laser ablation and MnAs grown on GaAs (produced by Ploog in Berlin), has identified important factors influencing the magnetisation process, domain formation and moment stability of these magnetic-semiconductor heterostructures. The project formed part of the EPSRC funded network on Hybrid magnetic/semi-conductor structures and spin electronics (spintronics). For this work Cropper received a Knowledge Transfer Award in 2004 for his partnership with Scientific Vacuum Systems Ltd.

The Department of Physics is a part of the research infrastructure of the Research School of Materials, which covers several departments. All of these departments have access to an extensive range of research equipment.

An interesting way to control and use spin degree of freedom is to design magnetic superconducting hybrids. One type of device we have described [J.E. Villegas, S. Savel'ev, F. Nori, E.M. Gonzalez, J.V. Anguita, R. Garcia, J.L. Vicent, Science 302, 1188 (2003)] is presented above. Superconducting vortices shown by blue and red circles interact with magnetic nano-triangles. This allows control of the motion of superconducting vortices.

Symposium in honour of Emmanuel Rashba's 80th birthday

Some recent PhD theses

• Mohamed S K Al-Busaidy, Energetic Deposition of thin metal films, 2001 (supervsor Cropper)
• Zahid B Asghar, Spin Density Waves in the Hubbard Model, 2001 (supervisor Samson)
• Endre Kovács, Numerical Simulation of Multi-particle Magnetic Systems, 2005 (supervisor Kusmartsev)
• Deborah C Barrett, Critical length for self-trapping and suppression of critical temperature for superconductivity in quasi one dimensional quantum nanowires of restricted size, 2007 (supervisor Kusmartsev)
• Anthony O'Hare, The formation of low temperature superstructures in the two-dimensional Ising model with next-nearest neighbour interactions, 2007 (supervisor Kusmartsev)
• Huseyin Nacak, Spintronics with domain walls in magnetic nanowires, in progress (supervisors Kusmartsev and Rashba)

Contacts

• Mike Cropper
• Kliment Kugel
• Karl Kürten
• Feo Kusmartsev
• Klaus Neumann
• Alexander Rakhmanov
• Emmanuel Rashba
• Sergey Savel'ev
• Kurt Ziebeck
• Alexander Balanov

For further information

O. Makarovsky, A. G. Balanov, L. Eaves, A. Patanè, R. P. Campion, C. T. Foxon, and R. J. Airey, “Using randomly distributed charges to create quantum dots” , Phys. Rev. B 81, 035323 (2010).

O. Makarovsky, O. Thomas, A. G. Balanov, L. Eaves, A. Patanè, R. P. Campion, C. T. Foxon, E. E. Vdovin, D. K. Maude, G. Kiesslich, and R. J. Airey, Fock-Darwin-Like Quantum Dot States Formed by Charged Mn Interstitial Ions, Phys Rev Lett 101 226807 (2008) (reviewed in Nature Nanotechnology 5 Dec 2008 and in Nature Materials 8, 5 2008 )

E I Rashba, Theory of electric dipole spin resonance in quantum dots: Mean field theory with Gaussian fluctuations and beyond, Phys Rev B 78 195302 (2008) (reviewed by Y Tokura in Nature Physics 5 12)

E I Rashba, Restrictions on modeling spin injection by resistor networks, Semiconductor Science and Technology 23 114015 (2008)

E I Rashba, Bruce and Electric Dipole Spin Resonances, presentation given at McCombe fest, Buffalo, March 2008

E I Rashba, Side jump contribution to spin−orbit mediated Hall effects and Berry curvature, Perel' memorial issue of Fizika i Tekhnika Poluprovodnikov 42, 923–926 (2008)

D M Forrester, K Kurten and F Kusmartsev, Magnetic cellular automata and the formation of glassy and magnetic structures from a chain of magnetic particles, Phys Rev B, 74, 014416 (2007)

D M Forrester, K Kurten and F Kusmartsev, Two-particle element for magnetic memory, Phys Rev B 76, 134404 (2007)

K Kurten and F Kusmartsev, Fractal structures in systems made of small magnetic particles, Phys Rev B 72, 014433 (2005)

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