Dr Wayne Hutchison Senior Lecturer BSc, PhD UNSW, MAIP, MVSA School of Physical, Environmental and Mathematical Sciences UNSW @ ADFA Canberra   ACT   2600 AUSTRALIA Phone: +61 2 626 88804 Fax: +61 2 6268 8786 Email: w.hutchison@adfa.edu.au Location: PEMS Sth, Room G22

Research Interests:

Advanced Materials

Wayne Hutchison has a strong research background in magnetic resonance, in particular with regard to nuclear magnetic resonance (NMR), the very low temperature technique of NMR on oriented nuclei (NMRON) and, most recently, electron spin resonance (ESR).

First and foremost, he runs the magnetic resonance program as part of the Centre for Quantum Computer Technology (See http://www.qcaustralia.org). The general aim of this program is the application of magnetic resonance, directly, to measurements on spin systems which have application as spin based quantum computers (QC). The emphasis is on ESR studies of the phosphorus in silicon (Si:P) system. The technique is also applied to investigations of the principal materials and fabrication processes.

Another research interest is the experimental investigation of rare earth based intermetallic compounds, in particular the intriguing RNiAl₄ series (R = rare earth). This involves a range of techniques from bulk magnetic measurements to low temperature nuclear orientation (LTNO) and neutron diffraction. A third project is the application of the millikelvin techniques of LTNO and NMRON to dilute magnetic alloys and magnetic insulating compounds with interesting very low temperature behaviour. In particular, he is presently exploring the application of the enhanced nuclear paramagnet, HoF₃ as a magnetic refrigerant at very low temperatures. Wayne is also involved in a project to study ion beam synthesis and modification of nanostructures (crystals, wires and layers).

Current Research

Magnetic resonance program (Dr Wayne Hutchison, Nakorn Suwuntanasarn, Natasa Bulatovic with Dr Richard Bramley, Prof. Martin Brandt, Prof. Robert Clark, Dr Jeff McCallum, Dr Eric Gauja, Hans Huebl, Dr Greg Milford, Prof. Steven Prawer, Dr Paul Spizzirri, Nikolas Stavrias & Dr Laurens Willems van Beveren)

The broad aim of this program is the use of magnetic resonance, directly, for measurements on spin systems which have application as spin based quantum computers (QC). The technique is also applied to investigations of the principal materials and fabrication processes. The emphasis is on electron spin resonance (ESR) studies of the phosphorus-in-silicon (Si:P) system.

Pulsed ESR for coherence time measurements

One of the attractions of a spin based quantum computer is the prospect of long coherence times. In this project, pulsed electron spin resonance (ESR) is applied to ensembles of phosphorus spins in silicon to explore this experimentally. The spin coherence time is expected to increase with reduction in temperature and of the concentration of both the phosphorus donors and host ²⁹Si isotope (non-zero nuclear spin. A pulsed ESR system has been developed that can operate in conjunction with an electro-magnet down to 4 K, or with a dilution refrigerator and superconducting solenoid magnet down to millikelvin (mK) temperatures. At very low temperatures the Si:P spin-lattice relaxation time becomes very long and is then an impediment to signal averaging over many pulse cycles. In our systems a pulse of light applied immediately following each echo is used to facilitate faster relaxation. Based on measurements to date, it is anticipated that an isolated spin coherence time of approximately 100 ms will be achieved at 1 K for a sample with 10¹⁵ cm^-3 phosphorus donors.

Swept field ESR measurements

Conventional (swept field) ESR is also used to investigate large area Si:P implants (ensembles) produced via implantation of P⁺ and molecular P²⁺ at the University of Melbourne. Focus continues on examination of various preparation methods with a view to maximise donor activation, as viewed by ESR, and to minimise unwanted charge traps, which are mostly associated with the implantation process itself. Poor donor activation has been observed when using low energy implantation into substrates with surface oxides and this is a non-trivial issue to resolve. So far there is a strong indication that donor electrons are being poached by traps when the donors are placed near to the surface (i.e. the donors are effectively compensated by interfacial traps).

There are many approaches to improve the yield of low energy implants and ESR can be applied as a diagnostic. Such studies complement photoluminescence and Raman spectroscopy measurements, as well as identifying suitable samples for coherence time studies. This technique also allows for the testing of fabrication processes which produce high quality device oxides with low trap densities, which will be required for sensitive QC devices.

Nature and influence of the crystal field interaction at the rare earth site in intermetallic compounds (Assoc. Prof. Glen Stewart , Banchachit Saensunon & Dr Wayne Hutchison with Dr Paul Gubbens, Assoc. Prof. Hiko Nishimura & Prof. Dominic Ryan)

Banchachit Saensunon's thesis work is directed at the influence of the crystal field interaction in rare earth intermetallic compounds. The first part of this project extends a systematic investigation of the crystal field interaction for the isostructural series RT₂Si₂ (R = rare earth, T = Cu, Ni, Co, Fe) to include T = Mn and Cr. The nature of the crystal field interaction in intermetallic compounds is complicated by the presence of itinerant electrons and the purpose of his investigation is to compare how the methods of Mössbauer spectroscopy and inelastic neutron scattering cope with this. The second part of the thesis project is being conducted in collaboration with Wayne Hutchison and Hiko Nishimura and looks at the crystal field origins of intriguing magnetic behaviour of the intermetallic series RNiAl₄.

Radar absorbing properties of doped barium hexaferrite (Assoc. Prof. Glen Stewart & Dr Wayne Hutchison)

A series of student projects was directed at the radar absorbing properties of barium hexaferrite when its trivalent iron content was substituted with increasing concentrations of different tetravalent-divalent transition metal pairs. The microwave network analyser measurements were performed at DSTO's Maribyrnong site.

Radioisotope tracing of sediment transport (Dr Heiko Timmers & Dr Wayne Hutchison with Assoc. Prof. Jacky Croke, Dr Chris Thompson & Dr J. Fernandez-Niello)

Sediment transport along rivers and creeks is an important environmental issue. In this work we have established measurement facilities in the School to quantify sediment transport using the radioisotopes Cs-137, Pb-210 and Be-7. Experiments in progress are relevant to the Fitzroy river basin and local ACT forest management.

Recent achievements

Design and commissioning of low temperature, pulsed, electron spin resonance facility (Dr Wayne Hutchison & Nakorn Suwuntanasarn)

A pulsed ESR system has been developed that can operate in conjunction with a dilution refrigerator and superconducting solenoid magnet down to millikelvin (mK) temperatures. Using this system we have recorded the longest reported coherence times for phosphorus donors in natural silicon (~4 ms) and also, the longest for an isotopically enriched 28Si host with a donor concentration around 10¹⁶ cm^-3 at ~10 ms.

Assoc. Prof. Glen Stewart, Nakorn Suwuntanasarn (Wayne's PhD student) & Dr Wayne Hutchison in front of one of the Advanced Materials group's two 3 He- 4 He dilution refrigerators, with a base operating temperature of 6 millikelvin.

Electron spin resonance detection of 50 P atoms implanted in a silicon host (Dr Wayne Hutchison)

Electrical detection of magnetic resonance (EDMR) uses spin dependent scattering of a (photo) current to greatly enhance sensitivity. EDMR measurements on Si:P devices carried out jointly with UNSW, Walter Schottky Institute and University of Melbourne showed magnetic resonance was observed for ~85 P cluster implanted P donors (Applied Physics Letters, 89, 182115 (2006)). In 2006, fabrication of a new batch of devices, with arsenic leads was undertaken. The resulting EDMR confirms unequivocally that a signal can be observed from about 50 implanted donor .

Research Collaborators

• School of PEMS, UNSW@ADFA: A/Prof Glen Stewart, Dr Heiko Timmers, Dr Stephen Harker, A/Prof Don Chaplin
  
• University of Toyama, Japan: Prof. Katsuhiko Nishimura, Prof Y. Yishikawa, Prof K. Mori
  
• University of Niigata, Japan: Prof Susumu Ohya.
  
• University of Melbourne: Dr Jeff McCallum, Prof Steven Prawer, Dr Paul Spizzirri, Mr Nikolas Stavrias
  
• University of New South Wales: Prof Robert Clark, Dr Eric Gauja, Dr Laurens Willems van Beveren, Dr Hans Huebl
  
• ANU, Research School of Chemistry: Dr Richard Bramley, Dr Darren Gossens
  
• Walter Schottky Institute, Technical University Munich: Prof Dr Martin Brandt
  
• University of Southampton, UK: Prof Graham Bowden
  
• ANSTO, Sydney: Dr Andrew Studer, Dr Max Aardeev

Research Agreements

Academic exchange between UNSW@ADFA, School of PEMS and the University of Toyama, Graduate School of Science and Engineering.

Prof. Katsuhiko Nishimura from the University of Toyama is a regular visitor to UNSW@ADFA. His long standing collaborative research work with Dr Wayne Hutchison and the Advanced Materials Group was the basis of an agreement for Academic exchange between UNSW@ADFA, School of PEMS and the University of Toyama, Graduate School of Science and Engineering. The agreement was instigated some 5 years ago and was recently renewed. Katsuhiko and Wayne were joined by staff to witness the signing of the renewed agreement.

Standing from L to R: Danica Robinson (Research & Research Training Office), Assoc. Prof. Glen Stewart (Physics Discipline coordinator), Dr Wayne Hutchison, Dr Glenn Banks (Acting HOS, PEMS). Seated from L to R: are the Rector, Prof. John Baird and Assoc. Prof. Katsuhiko Nishimura. (Photograph by David Paterson, ETS, UNSW@ADFA).

Recent Publications

In press:

Bulatovic, N., Hutchison, W.D., Spizziri, P.G., McCallum, J.C., Stavrias, N. & Prawer, S., in press, A study of the activation of ion implanted phosphorus donors in silicon using ESR, Proceedings of 32nd Annual ANZIP Condensed Matter and Materials Meeting, Wagga Wagga 2008, submitted.

Hutchison, W.D., Chaplin, D.H. & Nishimura, K., in press, Low temperature nuclear orientation observations of severe neutron activation damage in (¹⁶⁰Tb)TbNiAl₄, Hyperfine Interactions.

Hutchison, W.D., Saensunon B. & Stewart, G.A., in press, Magnetic ordering temperatures across the RNiAl₄ series, Proceedings of the 32nd Annual ANZIP Condensed Matter and Materials Meeting, Wagga Wagga 2008, submitted.

Suwuntansarn, N. , Hutchison, W. D. , Milford G. N. & Bramley, R., in press, Novel pulsed electron spin resonance system and studies of phosphorus in natural silicon, Hyperfine Interactions.

Journal article refereed:

Nishimura, K., Mori, K., Narita, Y. & Hutchison, W.D., 2007, Magnetic anisotropy of Nd_1-x Gd_x Ni single crystals, Journal of Magnetism and Magnetic Materials, 310(2), 1730-1731.

Hutchison, W.D. , Goossens, D.J., Nishimura, K., Mori, K., Isikawa, Y. & Studer, A.J., 2006, Magnetic structure of TbNiAl₄, Journal of Magnetism and Magnetic Materials, 301(2), 352-358.

McCamey, D.R., Huebl, H., Brandt, M.S., Hutchison, W.D. , McCallum, J.C., Clark, R.G. & Hamilton, A.R., 2006, Electrically detected magnetic resonance in ion-implanted Si:P nanostructures, Applied Physics Letters, 89(18), 182115-182117.

Conference - full paper refereed:

Hutchison, W.D., Goossens, D.J., Saensunon, B., Stewart, G.A., Avdeev, M. & Nishimura, K., 2007, Magnetic order studies of ErNiAl₄, Proceedings of the 31st Annual Condensed Matter and Materials Meeting, Wagga Wagga, 6-9 February 2007, pp. 42-44. Available at: http://www.aip.org.au/wagga2007/2007_10.pdf

Hutchison, W.D. & Nishimura, K., 2007, Wide ranging studies of magnetism in RNiAl₄ compounds, Proceedings of 2007 Japan-China-Australia Cooperative Symposium on Materials Science and Nanotechnology, University of Toyama, pp. 1-7, ISBN978-4-9903248-1-0.

Suwuntanasarn, N. , Hutchison, W.D., Milford, G. & Bramley, R., 2007, A novel probehead for an electron spin echo study of an Australian coal, Proceedings of the 31 st Annual Condensed Matter and Materials Meeting, Wagga Wagga, 6-9 February 2007, pp. 93-95. Available at: http://www.aip.org.au/wagga2007/2007_27.pdf

Conference abstract:

Saensunon, B., Stewart, G.A., Gubbens, P.C.M., Hutchison, W.D. & Buchsteiner, A., 2007, The crystal field parameters for Er³⁺ in ErNiAl₄, Sixth AINSE/ANBUG Neutron Scattering Symposium (AANSS2007), Lucas Heights 4-6 December, 2007.

Hutchison, W.D., Goossens, D.J., Saensunon, B., Stewart, G.A., Avdeev, M. & Nishimura K., 2006, Magnetic studies of RNiAl₄, Fifth AINSE/ANBUG Neutron Scattering Symposium (AANSS2006), Lucas Heights, 11-13 December, 2006.

McCamey, D.R., Huebl, H., Brandt, M.S., Chan, V.C., Buehler, T.M., Ferguson, A., Hutchison, W.D., McCallum, J.C., Hamilton, A.R., Durak, A.S., Yang, C., Jamieson D.N., & Clark, R.G., 2006, Spin and charge properties probed using ion-implanted nanostructures, invited talk, International Workshop on Quantum Information Processing QIP 2006 - Herrsching, Germany 24-26 May 2006.

Saensunon, B., Stewart, G.A., Gubbens, P. C. M., Hutchison, W.D. & Buchsteiner, A., 2006, The crystal field scheme for Er³⁺ in ErNiAl₄, Fifth AINSE/ANBUG Neutron Scattering Symposium (AANSS2006), Lucas Heights, 11-13 December, 2006.

Conference poster:

Suwuntanasarn, N., Hutchison, W.D. & Milford, G.N., 2008 Low temperature X-band probe heads for decoherence time studies in semiconductors, poster, 32nd ANZIP Condensed Matter Meeting, Wagga Wagga 29 January-1 February 2008.

Hutchison, W.D., Bowden, G.J., & Norén, L., 2007, HoF₃ as a low temperature refrigerant, poster WP27, 31st ANZIP Condensed Matter Meeting, Wagga Wagga 6-9 February 2007.

Spizzirri, P., McCallum, J., Hutchison, W.D., Suwuntanasarn, N., Bulatovic, N., Stavrias, N. & Prawer, S., 2007, An EPR study on the activation of low energy phosphorus ions implanted in silicon, Proceedings of 15th Australian Conference on Nuclear and Complementary Techniques of Analyses & 9th Vacuum Society of Australia Congress, Australian Institute of Nuclear Science and Engineering, The University of Melbourne, 21-23 November 2007. Available at: http://www.ansto.gov.au/_data/assets/pdf_file/0020/24446/WebPages301-365PostersPt4.pdf

Hutchison, W.D. & Bowden, G.J., 2006, Two new low temperature refrigerators?, poster WP21, 30th ANZIP Condensed Matter Meeting, Wagga Wagga 7-10 February 2006.

Hutchison, W.D., Suwuntanasarn, N., Spizzirri, P.G., Stavrias, N., Prawer, S., McCallum, J.C., & Gauja, E., 2006, ESR studies of low energy ion-implanted P donors in silicon, poster, International Workshop on Quantum Information Processing QIP 2006 - Herrsching, Germany 24-26 May 2006.

Shrestha, S.K., Timmers, H., Byrne, A. P., Hutchison, W.D. , Chaplin D.H. & Dogra, R., 2006, Implantation of radioisotope probe 111In/Cd for materials studies, poster TP20, 30th ANZIP Condensed Matter Meeting, Wagga Wagga 7-10 February 2006.

Spizzirri, P.G., Hutchison, W.D. , Gauja, E., Stavrias, N., & Prawer, S., 2006, Silicon surface hydrogenation for low energy implantation, poster day 1, ARC ARAM Workshop, University of Queensland, 28-30 June 2006.

Spizzirri, P.G., McCallum, J.C., Hutchison, W.D., Milford, G., Suwuntanasarn, N., Stavrias, N,. Villis, B. & Prawer, S., 2006, Micro-Raman spectroscopy of Si:P systems, poster, NSA Quantum Computing Program Review, Atlanta USA , 14-16 August 2006.

Grants

External

R. G. Clark, G. J. Milburn, A. S. Dzurak, D. N. Jamieson, A. G. White, M. Simmons, T. Lehmann, H. Rubinstein-Dunlop, S. Prawer, L. Hollenberg, T. Ralph, J. C. McCallum, C. Pakes, H. Wiseman, G. R. Pryde, J. Twamley, I. Shparlinsky, D. R. MacKenzie, E. H. Huntington, W. D. Hutchison , D. Pulford, G. Klimeck, B. C. Saunders, R. Sharp, Centre for Quantum Computer Technology, ARC COE (renewal) 2008-2010: $10.1M ($270, 000 to WDH UNSW@ADFA).

W. D. Hutchison, Field dependence of TbNiAl 4 magnetic structure, AINSE, 2006: $11,900.

W. D Hutchison, Hyperfine studies via neutron activation, AINSE, 2006: $1,651.

G. A. Stewart, W. D. Hutchison & P. C. M. Gubbens, Application for access to NEAT time-of-flight spectrometer, Crystal field interaction for the intermetallic series RNiAl 4 (R = rare earth) Berlin Neutron Scattering Centre, 2006, 10 days beam time awarded.

R. G. Clark, G. J. Milburn, A. S. Dzurak, M. Y. Simmons, A. R. Hamilton, S. Prawer, D. N. Jamieson, L. C. Hollenberg, J. C. McCallum, C. I. Pakes, H. Rubinsztein-Dunlop, T. C. Ralph, A. G. White, B. C. Sanders, H. Wiseman, D. R. McKenzie, E. H. Huntington, W. D. Hutchison , D. Pulford, R. J. Hughes, P. C. Hammel, B. E. Kane, W. J. Munro & R. Sharp, Centre for Quantum Computer Technology, ARC COE, 2003-2008: $14.2M ($425, 000 to WDH UNSW@ADFA).

UNSW

H. Riesen, G. Stewart, S. Campbell, W. Hutchison, J. Croke, L. Wallace, R. McLean, S. Lo, R. Niven, O. Kayali & S. Yeomans ACME/ PEMS, Energy dispersive X-ray fluorescence spectrometer, RIBG: $30,186.

C. Harb, E. H. Huntington, W. D. Hutchison & G. Milford , High performance digital storage oscilloscope for research in trace gas analysis and quantum computer technology, RIBG, 2006: $32,890.

Service

• Executive committee member of the ACT Branch Australian Institute of Physics since 2000.
  
• Member of the International Advisory Committee for the International Conference on Hyperfine Interactions in 2007.