Prof Andrew Fisher

• Understanding coherent spin dynamics in rare-earth spin systems (with Gabriel Aeppli and others)
• The theory of quantum entanglement, especially in condensed-phase systems;
• Theory of quantum information processing and decoherence (with Sougato Bose, Ahsan Nazir, Alessio Serafini and others);
• The theory of electrical conduction through molecules and nanostructures, especially inelastic and local heating effects (with David Bowler, Andrew Horsfield and others);
• Theory of scanning tunnelling microscopy, especially IETS (Inelastic Electron Tunnelling Spectroscopy - with Werner Hofer and Geoff Thornton) and spin-dependent spectroscopy (with Cyrus Hirjibehedin).

I have wide research interests in theoretical nanoscience. I am particularly interested in the impact of quantum mechanics on the dynamics of nanostructures – for example, the flips of small clusters of spins, or the flow of current-carrying electrons though a molecule or an atomic-scale wire – and the extent to which interactions with other degrees of freedom can modify or damp out these quantum mechanical effects. The consequences of this work range from quite applied questions – how could one use quantum mechanics to process information, or make a transistor from a single molecule?– to rather fundamental ones – what is the macroscopic limit of quantum mechanics? I use a mixture of analytical and computational techniques and I like to work closely with experimentalists; several of my research students and postdoctoral research fellows are closely involved with experimental projects.

Research Group

I work with a number of LCN members, including the following research fellows and students:

• Dr Veronika Brazdova (joint with David Bowler)
• Dr Thornton Greenland
• Dr Dessie Nikolova (EU Marie-Curie Fellow)
• Dr Wei Wu (joint with Nicholas Harrison)
• Sareh Heidari
• Dara McCutcheon (with Sougato Bose, UCL Physics and Astronomy)
• Rafael Miranda (with Andrew Horsfield)
• George Pender (with Tania Monteiro, UCL Physics and Astronomy)

In addition I am second supervisor to Ben Warner, Jenny Oberg and Marc Warner.

Recent publications

ISI Researcher ID A-4723-2012

• H. C. Lin and A. J. Fisher, "Local entanglement of multidimensional continuous-variable systems," Phys. Rev. A 78 (1), 11 (2008).
• W. Wu and A. J. Fisher, "Exchange between deep donors in semiconductors: A quantum defect approach," Phys. Rev. B 77 (4), 11 (2008).
• W. Wu, A. Kerridge, A. H. Harker et al., "Structure-dependent exchange in the organic magnets Cu(II)Pc and Mn(II)Pc," Phys. Rev. B 77 (18), 12 (2008).
• G. Teobaldi, N. S. Beglitis, A. J. Fisher et al., "Hydroxyl vacancies in single-walled aluminosilicate and aluminogermanate nanotubes," J. Phys.-Condes. Matter 21 (19), 9 (2009).
• Long-lived spin entanglement induced by a spatially correlated thermal bath. D.P.S. McCutcheon, A. Nazir, S. Bose, and A. J. Fisher. Phys. Rev. A 80 022337 (2009). doi:10.1103/PhysRevA.80.022337
• Electron traps and their effect on the surface chemistry of TiO2(110). A.C. Papageorgiou, N.S. Beglitis, Chi L. Pang, G. Teobaldi, G. Cabailh, Qiao Chen, A.J. Fisher, W.A. Hofer and G. Thornton. Proc. Nat. Acad. Sci. (USA) 107 2391-2396 (2010).
• Separation-dependent localization in a two-impurity spin-boson model. Dara P. S. McCutcheon, Ahsan Nazir, Sougato Bose, and A.J. Fisher. Physical Review B 81 235321 (2010) 10.1103/PhysRevB.81.235321;
• Ultralong copper phthalocyanine nanowires with new crystal structure and broad optical absorption. Hai Wang, Soumaya Mauthoor, Salahud Din, Jules A. Gardener, Rio Chang, Marc Warner, Gabriel Aeppli, David W. McComb, Mary P. Ryan, Wei Wu, A. J. Fisher, A.M. Stoneham and Sandrine Heutz. ACS Nano 4 3921-3926 (2010). 10.1021/nn100782w
• Analog of Rabi oscillations in resonant electron-ion systems. L. Stella et al. Journal of Chemical Physics 134 (2011) DOI: 10.1063/1.3589165
• A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states. R.P. Miranda et al. Journal of Chemical Physics 134 (2011) DOI: 10.1063/1.3600397
• A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states. R.P. Miranda et al. Journal of Chemical Physics 134 (2011) DOI: 10.1063/1.3600397