Professor Ben Powell

Professor

Physics
Faculty of Science
powell@physics.uq.edu.au
+61 7 336 52401

Overview

This is an automatically generated university page - my real website is https://people.smp.uq.edu.au/BenPowell/

Qualifications

  • PhD, University of Bristol
  • MSc, University of Bristol

Publications

View all Publications

Supervision

  • Doctor Philosophy

  • Doctor Philosophy

  • Doctor Philosophy

View all Supervision

Available Projects

  • Condensed matter physicists sometimes pity our colleagues in high-energy physics. They are limited to studying a single vacuum and its excitations: the particles of the standard model. For condensed matter physicists every new phase of matter brings a new ‘vacuum’. Remarkably the low-energy excitations of these new vacua can be very different from the individual electrons, protons and neutrons that constitute the material. The condensed matter multiverse contains universes where the particle-like excitations carry only a fraction of the elementary electronic charge are magnetic monopole, or are their own antiparticle. None of these properties have ever been observed in the particles found in free space. Often emergent gauge fields accompany these ‘fractionalized’ particles, just as electromagnetic gauge fields accompany charged particles.

    In this project you will discover the nature of the particles that emerge a recently phase of matter – the spin-state ice – that is predicted to occur in spin crossover materials. You will develop new theories of these materials and seek to discover other exotic phases in them.

  • Some molecules are magnetic. Others are not. Spin-crossover molecules are unusual because they can be switched between magnetic (high-spin) and non-magnetic (more generally, low-spin) states by temperature, pressure, chemical environment, or irradiation by light. Furthermore, materials containing spin-crossover molecules can display phase transitions between states with different spatial patterns of molecules with high- and low-spin that have similarities to emergent states with magnetic, orbital and charge ordering, such as antiferromagnetism.

    The fundamental question you will investigate is: why does this happen? This will require the application of state-of-the-art computational methodologies to describe the quantum behavior of the electrons in these materials. Importantly, the electrons interact strongly with one another in these systems. This means that the behaviors are collective and the standard approaches to chemistry, where we treat each electron independently, fail miserably. Instead you will use supercomputers to model the collective physics.

  • Materials are vital for modern technology. Our understanding and control of the physics of silicon enabled the digital revolution. But electron-electron interactions are not important for the physics of silicon. In many other materials quantum mechanical electron-electron interactions determine the properties of the materials. These quantum materials show amazing properties such as high temperature superconductivity and sometime have excitations that are very different from the properties of the vacuum [1]. If we could routinely design and control quantum materials it would revolutionise technologies from electricity distribution to computing. But currently we have very limited abilities to design quantum materials. A new class of materials, MOFs, may be the key to enabling the rational design of quantum materials. Several projects are available in this area using techniques varying from supercomputer calculations to pen and paper theory to help change this in collaboration with world leading synthetic chemists and experimental physicists.

    [1] B. J. Powell, The expanding materials multiverse, Science 360, 1074 (2018)

View all Available Projects

Publications

Book Chapter

  • Mostert, A. B., Meredith, P., Powell, B. J., Gentle, I. R., Hanson, G. R and Pratt, F. L. (2016). Understanding melanin: A nano-based material for the future. Nanomaterials: science and applications. (pp. 175-202) edited by Deborah Kane, Adam Micolich and Peter Roger. Boca Raton, FL, United States: Pan Stanford.

  • Powell, Ben J. (2011). An introduction to effective low-energy Hamiltonians in condensed matter physics and chemistry. Computational methods for large systems: Electronic structure approaches for biotechnology and nanotechnology. (pp. 309-366) edited by Jeffrey R. Reimers. Hoboken, NJ, United States: Wiley. doi: 10.1002/9780470930779.ch10

  • Meredith, Paul, Powell, Ben J., Riesz, Jenny, Vogel, Robert, Blake, David, Kartini, Indriani, Will, Geff and Subianto, Surya (2006). Broadband Photon-harvesting Biomolecules for Photovoltaics. Artificial Photosynthesis: From Basic Biology to Industrial Application. (pp. 35-65) Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA. doi: 10.1002/3527606742.ch3

Journal Article

Conference Publication

  • Lanyon, Benjamin P., Whitfield, James D., Gillett, Geoffrey G., Goggin, Michael E., Almeida, Marcelo P., Kassal, Ivan, Biamonte, Jacob D., Mohseni, Masoud, Powell, Benjamin J., Barbieri, Marco, Aspuru-Guzik, Alan and White, Andrew G. (2011). Simulating quantum systems in biology, chemistry, and physics. 241st National Meeting and Exposition of the American-Chemical-Society (ACS), Anaheim Ca, Mar 27-31, 2011. WASHINGTON: AMER CHEMICAL SOC.

  • Mutkins, Karyn, Chen, Simon S. Y., Aljada, Muhsen, Powell, Ben J., Olsen, Seth, Burn, Paul L. and Meredith, Paul (2011). Charge transport properties of carbazole dendrimers in organic field-effect transistors. Conference on Organic Field-Effect Transistors X, San Diego, United States, 22-23 August 2011. Bellingham, WA, United States: S P I E - International Society for Optical Engineering. doi: 10.1117/12.892640

  • Meredith, P., Mostert, B., Gentle, I. R., Hanson, G., Tandy, K., Namdas, E., Pratt, F. and Powell, B. J. (2011). Is melanin a semiconductor: The mysteries of electrical conduction and melanin bioelectronics?. ipcc2011: International Pigment Cell Conference. Skin and Other Pigment Cells: Bridging Clinical Medicine and Science, Bordeaux, France, 20-24 September 2011. Malden, MA, U.S.A.: Wiley-Blackwell Publishing. doi: 10.1111/j.1755-148X.2011.00885.x

  • Lanyon, B. P., Whitfield, J. D., Gillett, G. G., Goggin, M. E., Almeida, M. P., Kassal, I., Biamonte, J. D., Mohseni, M., Powell, B. J., Barbieri, M., Aspuru-Guzik, A. and White, A. G. (2009). Quantum chemistry on a quantum computer: First steps and prospects. Laser Science, LS 2009, San Jose, CA, United States, 11 - 15 October 2009. Washington, D.C.: Optical Society of America. doi: 10.1364/fio.2009.jwd3

  • Quintanilla, J., Hooley, C., Powell, B. J., Schofield, A. J. and Haque, M. (2008). Pomeranchuk instability: Symmetry-breaking and experimental signatures. SCES2007: International Conference on Strongly Correlated Electron Systems, Houston, TX, USA, 13-18 May, 2007. Amsterdam, Netherlands: Elsevier. doi: 10.1016/j.physb.2007.10.126

  • Pederson, Mark R., Anderson, W. A., Baruah, Tunna and Powell, B. J. (2006). Massively parallel simulations on light-induced charge transfer in molecules. HPCMP Users Group Conference (HPCMP-UGC'06), Denver CO, United States, 26-29 June 2006. Piscataway, NJ United States: IEEE. doi: 10.1109/HPCMP-UGC.2006.44

  • Powell, B. J. (2004). The origin of the difference in the superconducting critical temperatures of the beta(H) and beta(L) phases of (BEDT-TTF)(2)I-3. Les Ulis Cedexa: EDP Sciences. doi: 10.1051/jp4:2004114084

  • Powell, B. J., Annett, J. F. and Gyorffy, B. L. (2002). The behaviour of a triplet superconductor in a spin only magnetic field. International Conference on Ruthenate and Rutheno-Cuprate Materials, Vietri sul Mare, Italy, 25-27 October 2001. Berlin, Germany: Springer.

Other Outputs

Grants (Administered at UQ)

PhD and MPhil Supervision

Current Supervision

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

  • Doctor Philosophy — Associate Advisor

    Other advisors:

Completed Supervision

Possible Research Projects

Note for students: The possible research projects listed on this page may not be comprehensive or up to date. Always feel free to contact the staff for more information, and also with your own research ideas.

  • Condensed matter physicists sometimes pity our colleagues in high-energy physics. They are limited to studying a single vacuum and its excitations: the particles of the standard model. For condensed matter physicists every new phase of matter brings a new ‘vacuum’. Remarkably the low-energy excitations of these new vacua can be very different from the individual electrons, protons and neutrons that constitute the material. The condensed matter multiverse contains universes where the particle-like excitations carry only a fraction of the elementary electronic charge are magnetic monopole, or are their own antiparticle. None of these properties have ever been observed in the particles found in free space. Often emergent gauge fields accompany these ‘fractionalized’ particles, just as electromagnetic gauge fields accompany charged particles.

    In this project you will discover the nature of the particles that emerge a recently phase of matter – the spin-state ice – that is predicted to occur in spin crossover materials. You will develop new theories of these materials and seek to discover other exotic phases in them.

  • Some molecules are magnetic. Others are not. Spin-crossover molecules are unusual because they can be switched between magnetic (high-spin) and non-magnetic (more generally, low-spin) states by temperature, pressure, chemical environment, or irradiation by light. Furthermore, materials containing spin-crossover molecules can display phase transitions between states with different spatial patterns of molecules with high- and low-spin that have similarities to emergent states with magnetic, orbital and charge ordering, such as antiferromagnetism.

    The fundamental question you will investigate is: why does this happen? This will require the application of state-of-the-art computational methodologies to describe the quantum behavior of the electrons in these materials. Importantly, the electrons interact strongly with one another in these systems. This means that the behaviors are collective and the standard approaches to chemistry, where we treat each electron independently, fail miserably. Instead you will use supercomputers to model the collective physics.

  • Materials are vital for modern technology. Our understanding and control of the physics of silicon enabled the digital revolution. But electron-electron interactions are not important for the physics of silicon. In many other materials quantum mechanical electron-electron interactions determine the properties of the materials. These quantum materials show amazing properties such as high temperature superconductivity and sometime have excitations that are very different from the properties of the vacuum [1]. If we could routinely design and control quantum materials it would revolutionise technologies from electricity distribution to computing. But currently we have very limited abilities to design quantum materials. A new class of materials, MOFs, may be the key to enabling the rational design of quantum materials. Several projects are available in this area using techniques varying from supercomputer calculations to pen and paper theory to help change this in collaboration with world leading synthetic chemists and experimental physicists.

    [1] B. J. Powell, The expanding materials multiverse, Science 360, 1074 (2018)

  • A room temperature, ambient pressure superconductor would change the world. We could plant "farms" of solar panels in the outback and losslessly transport the energy generated to capital cities and Asia, dramatically lowering the cost of power generation. But the world record for the highest temperature ambient pressure superconductor hasn't increased in decades.

    However, new types of materials have recently emerged that can be clicked together like lego. This offers us the chance to design new materials with taylored propoerties from the ground up. However, doing so is a formidable theoretical challenge that requires understanding the quantum mechanical behaviours of 10^23 electrons simulatneously? In this project you will develop and apply new theoretical techniques to attack this problem.