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Andrew Rushforth

Associate Professor, Faculty of Science

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Biography

2014 - present: Assistant Professor, School of Physics and Astronomy, University of Nottingham.

2009 - 2014 : Senior Research Fellow, School of Physics and Astronomy, University of Nottingham.

2005 - 2009: Research Associate, School of Physics and Astronomy, University of Nottingham.

2001 - 2005: Research Associate, Cavendish Laboratory, Cambridge University.

Research Summary

My research interests include the investigation of new phenomena and novel functionalities in ferromagnetic metals and dilute magnetic semiconductors. In particular, I am interested in how… read more

Selected Publications

Current Research

My research interests include the investigation of new phenomena and novel functionalities in ferromagnetic metals and dilute magnetic semiconductors. In particular, I am interested in how magnetostriction and electrical gating can be used to control the magnetic state of nanoscale magnetic structures.

Many of the components in modern technological devices such as computers, communications devices (e.g. mobile phones) and sensors are made on a very small scale from magnetic materials. For example, modern computer hard drives and magnetic random access memory (MRAM) contain magnetic elements that are a few tens of nanometres in size. In such devices the direction of the magnetisation of the magnetic elements is used to store information. Controlling the direction of magnetisation is achieved by using electrical current to generate a magnetic field locally or by passing an electrical current through the device using an effect called "spin transfer torque". These techniques have disadvantages arising from the energy dissipated in applying electrical currents, the limits on miniaturisation (due to the need to integrate the components which generate the field with other magnetic devices) and the difficulty in addressing individual elements due to stray magnetic fields.

A solution to these problems would be to create devices in which the magnetic state is controlled by applying electrical voltages. One of the approaches adopted in my research involves combining the magnetic material with piezoelectric material in hybrid devices. Piezoelectric material has the property that it will physically expand or contract when an electrical voltage is applied to it. This can be used to transfer strain to the magnetic material. Certain magnetic materials possess a large magnetostriction, which means that if they are strained then the magnetisation direction will rotate. An example is the magnetostrictive transition metal alloy FeGa. We study the magnetic properties of these materials in the bulk and on the nanoscale using modern characterisation techniques such as Superconducting Quantum Interference Device (SQUID) magnetometry and Magnetic Force Microscopy (MFM), and we use state of the art growth and fabrication techniques (e.g. sputter deposition and electron beam lithography) to fabricate devices a few tens of nanometres in size. By conducting electrical transport experiments at GHz frequencies (comparable to the frequencies used in modern computing technology) we aim to demonstrate ultra-fast switching of the magnetic state of the devices by applying ultra-fast (10s of picoseconds) voltage pulses. The nanoscale devices are also used to study the fundamental physics of phenomena such spin transfer torque and the motion of magnetic domain walls.

Past Research

My previous position was as a Research Associate in the Semiconductor Physics Group at the Cavendish Laboratory in Cambridge, UK (2001-2005). My work involved investigating the electrical transport properties of coupled quantum dot systems with a view to their potential application as qubits in quantum computation.

School of Physics and Astronomy

The University of Nottingham
University Park
Nottingham NG7 2RD

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