I am a Postdoctoral Research Fellow specialising in high pressure techniques, working with Dr Paul Goddard to use pressure, magnetic fields and low temperatures to tune and study low-dimensional magnetic materials and superconductors.
I completed my undergraduate degree in physics at the University of Oxford, with my masters thesis on the development of proximity-detector-oscillators for use in pulsed magnetic fields. Following this I moved on to a PhD at the University of Cambridge under Dr Siddharth Saxena, graduating in 2017. My specialisation was in the use of high pressure to tune quantum criticality in ferroelectric systems and Mott transitions in 2D insulating antiferromagnets.
My first postdoctoral position was in the Emergent Phenomena Group of the IBS Centre for Correlated Electron Systems at Seoul National University, under Prof Je-Geun Park. Here I headed the van-der-Waals materials team and continued my investigation into Mott transitions and the tuning of low-dimensional magnetism with pressure, including synchrotron and neutron scattering studies. I then joined the Superconductivity and Magnetism group at Warwick in March 2019.
My current work focuses on the tuning of low-dimensional quantum magnet systems and materials which exhibit unconventional superconductivity through hydrostatic pressure, low temperatures, and ultra-high magnetic fields. The use of metal-organic framework, or coordination-polymer, crystalline materials leads to sufficiently low magnetic exchange energies to address the full magnetic phase diagram with achievable fields, and a rich variety of pressure effects on the organic ligands and exchange pathways linking magnetic sites.
SquidLab - Magnetic Background Subtraction Software
I am the lead developer on the 'SquidLab' software suite,for subtracting magnetic backgrounds in magnetisation data. SquidLab is written in Matlab, designed to be flexible and customisable, and is free to download with full editable source code under Academic Licence.
- M.J. Coak, C. Liu, D.M. Jarvis, S. Park, M.J. Cliffe and P.A. Goddard, SquidLab - A user-friendly program for background subtraction and fitting of magnetization data Rev. Sci. Instr. 91-2 (2020)
- M.J. Coak, D.M. Jarvis, H. Hamidov, C.R.S. Haines, P.L. Alireza, C. Liu, S. Son, I. Hwang, G.I. Lampronti, D. Daisenberger, P. Nahai-Williamson, A.R. Wildes, S.S. Saxena and J-G Park, Tuning dimensionality in van-der-Waals antiferromagnetic Mott insulators TMPS3 J.Phys.: Cond. Mat. (Emerging Leaders Special Issue) 32-12 (2019)
- H. Kim, M.J. Coak, J.C. Baglo, K. Murphy, R.W. Hill, M. Sutherland, M. Ciomaga Hatnean, G.
Balakrishnan and J-G. Park, Modular thermal Hall effect measurement setup for fast-turnaround screening of materials over wide temperature range using capacitive thermometry Rev. Sci. Instr. 90-10 (2019)
- M.J. Coak, C.R.S. Haines, C.Liu, G.G. Guzman-Verri and S.S. Saxena, Pressure dependence of ferroelectric quantum critical fluctuations Phys.Rev. B 100 (2019)
- M.J. Coak, Y.-H. Kim, Y.S. Yi, S. Son, S. K. Lee and J.-G. Park, Electronic and vibrational properties of the two-dimensional Mott insulator V0:9PS3 under pressure Phys. Rev B 100-3 (2019)
- M.J. Coak, S. Son, D. Daisenberger, H. Hamidov, C.R.S. Haines, P.L. Alireza, A.R. Wildes, C. Liu, S.S. Saxena and J-G. Park, Isostructural Mott transition in 2D honeycomb antiferromagnet V0.9PS3 npj Quant. Mat. 4-1 (2019)
- I. Hwang, M.J. Coak, N. Lee, D.-S. Ko, Y. Oh, I. Jeon, S. Son, K. Zhang, J. Kim and J-G Park, Hard ferromagnetic van-der-Waals metal (Fe,Co)3GeTe2: a new platform for the study of low-dimensional magnetic quantum criticality J.Phys.: Cond. Mat. 31-50 (2019)
- S. Son, M.J. Coak, N. Lee, J. Kim, T.Y. Kim, H. Hamidov, H. Cho, C. Liu, D.M. Jarvis, P.A.C.
Brown, J.H. Kim, C.-H. Park, D.I. Khomskii, S.S. Saxena and J.-G. Park, Bulk properties of the van-der-Waals hard ferromagnet VI3 Phys. Rev. B (R) 99-4 (2019)
- M.J. Coak, C.R.S. Haines, C.Liu, D.M. Jarvis, P.B. Littlewood and S.S. Saxena, Dielectric response of quantum critical ferroelectric as a function of pressure Scientific Reports 8-1 (2018)
- C.R.S. Haines, M.J. Coak, G.I. Lampronti, C.Liu, H. Hamidov, A.R. Wildes, D. Daisenberger, P. Nahai-Williamson and S.S. Saxena, Pressure-induced electronic and structural phase evolution in the van-der-Waals compound FePS3 Phys. Rev. Lett. 121-26 (2018)
- A. Yogi, C.I. Satish, H. Sim, M.J. Coak, Y. Noda and J.-G. Park, Symmetry breaking and unconventional charge ordering in single crystal Na2.7Ru4O9 Phys.Rev. B 98-8 (2018)
- J.B. Kargin, C.R.S. Haines, M.J. Coak, C.Liu, A.V. Matovnikov, V.V. Novikov, A.N. Vasiliev and S.S. Saxena, Low temperature resistivity of the rare earth diborides (Er, Ho, Tm)B2 Springer Proceedings in Physics 164 (2015)
- S. Ghannadzadeh, M.J. Coak, I. Franke, P.A. Goddard, J.Singleton and J.L. Manson, Measurement of magnetic susceptibility in pulsed magnetic fields using a proximity detector oscillator Rev. Sci. Instr 82-11 (2011)
Department of Physics
University of Warwick
Coventry CV4 7AL
+44 (0)2476 574760
matthew dot coak at warwick dot ac dot uk