Prof Jöerg Wunderlich

Research Interests

• Spintronics

My research activities have been focusing on magnetism and spintronics. I joined Hitachi Cambridge Laboratory in March 2001 after I finished my Ph.D. in Physics at the Institut d'Électronique Fondamentale in Orsay (France) and the Max Planck Institute in Halle (Saale), on “Extraordimary Hall effect and dynamics of magnetization reversal in ultrathin ferromagnetic stripes”. I then work on newly discovered spin effect in semiconductors : the Spin Hall Effect (SHE), the Coulomb Blockade Anisotropic Magnetoresistance effect (CBAMR) and the Spin Injection Hall effect (SIHE).

Recent Research projects

    My Current Research activities comprise spin-transport, spin-generation and spin-detection in semiconductor systems with reduced dimensionality and spin-polarized electronic transport in hybrid systems and patterned diluted ferromagnetic semiconductor nanostructures. Apart from the longstanding collaboration between Hitachi Cambridge Laboratory and the Microelectronic research centre (MRC) of the University of Cambridge in particular with Dr. Andrew C. Irvine and Dr. Andrew J. Ferguson, my work is embedded within many internal and external collaborations. In particular I collaborate with Prof. Tomas Jungwirth and his colleagues from the Department of Spintronics and Nanoelectronics, Department of Semiconductors, and Theory Department of the Institute of Physics, Academy of Science, Czech Republic, with the group of Petr Nemec from the Charles University in Prague and with Prof. Claude Chappert from the NanoSpintronics Group at the Institut d'Electronique Fondamentale in Orsay, France. I also work on joint projects with Dr. Bruce Gurney et al. from HGST, San Jose, USA, with the spintronic group of Prof. Bryan Gallagher at the Nottingham University, UK, and with Prof. Jairo Sinova from the Texas A&M University.
    One of the main outcomes of our work was the first observation of the Spin Hall effect (SHE) in a modulation doped 2DHG structure, published in Physical Review Letters in February 2005 [1]. This paper is already cited more than 400 times and described in a “News” article in Physics Today. Our findings on the spin Hall effect were obtained in parallel to results obtained in a different system by the group of David Awschalom in Santa Barbara: while D. Awschalom and colleagues observed the spin Hall effect of extrinsic nature (due to impurities), we revealed an effect of intrinsic characteristic of pure material.
    Another recent result was the first demonstration of a new effect, called Coulomb Blockade Anisotropic Magnetoresistance (“CBAMR”) [2]. CBAMR allows voltage control of this magnetoresitive effect and therefore the development of non-volatile logic circuits. To generate this effect we have created a simple device made of a single ferromagnetic material which demonstrates the first magnetic transistor with more than three orders of magnitude resistance change between “on” and “off” state. The simplicity of the device, the additional functionality, the magnitude of the effect, and its miniscule dimensions may have great potential in magnetic sensor, memory and logic chip technologies, such as computer hard-drive read heads or magnetic random access memories and CPUs.
    Our very recent result concerns the realization of a spin-sensitive photo-voltaic cell which directly converts circularly polarized light into transverse voltage signals. The discovery of the Spin injection Hall effect (SIHE) observed in a quasi-2D photovoltaic cell opens new means for integrating photonics and spintronics and provides a new tool for efficient and non-destructive detection of spins carried by electrical currents in conventional non-magnetic semiconductors. The findings are featured in the original paper published in Nature Physics, and in the accompanying News&Views article [3].

References :

1. J. Wunderlich, B. Kaestner, J. Sinova and T. Jungwirth, Phys. Rev. Lett. 94, 047204 (2005), Ch. Day, Physics Today, Feb. 2005, 17 - 19 Experimental Observation of the Spin-Hall Effect in a Two-Dimensional Spin-Orbit Coupled Semiconductor System
2. J. Wunderlich, T. Jungwirth, B. Kaestner, A. C. Irvine, A. B. Shick, N. Stone, K.-Y. Wang, U. Rana, A. D. Giddings, C. T. Foxon, R. P. Campion, D. A. Williams and B. L. Gallagher Phys. Rev. Lett. 97, 077201 (2006) Coulomb Blockade Anisotropic Magnetoresistance Effect in a (Ga,Mn)As Single-Electron Transistor
3. J. Wunderlich, A. C. Irvine, J. Sinova, B. G. Park, L. P. Zârbo, X. L. Xu, B. Kaestner, V. Novák and T. Jungwirth, Nature Physics 5, 675 (2009) Spin-injection Hall effect in a planar photovoltaic cell

Last Publications

• R. Rama-Eiroa, P. E. Roy, J. M. Gonzalez, K. Y. Guslienko, J. Wunderlich, and R. M. Otxoa, J. Magn. Magn. Mater. 560, (2022), Inertial domain wall characterization in layered multisublattice antiferromagnets

• J. P. Patchett, M. Drouhin, J. W. Liao, Z. Soban, D. Petit, J. Haigh, P. Roy, J. Wunderlich, R. P. Cowburn, and C. Ciccarelli, Phys. Rev. B 105, 10, (2022), Symmetry effects on the static and dynamic properties of coupled magnetic oscillators

• R. M. Otxoa, P. E. Roy, R. Rama-Eiroa, J. Godinho, K. Y. Guslienko, and J. Wunderlich, Commun. Phys. 3, 1, 190 (2020), Walker-like domain wall breakdown in layered antiferromagnets driven by staggered spin-orbit fields