Daniel Wisniewski
Daniel Wiśniewski
MR 28, Sir Peter Mansfield Magnetic Resonance Centre
University Park
University of Nottingham
Nottingham NG7 2RD
daniel.wisniewski@nottingham.ac.uk
PhD Student at the University of Nottingham; member of the Centre of Doctoral Training in Integrated Magnetic Resonance
Studied MSci Chemistry and Molecular Physics at the University of Nottingham, graduated with a 1st class honours degree.
My research focus is on spin dynamics in Dynamic Nuclear Polarization (DNP). The technique relies on transfer of polarization from an electron to nearby nuclei. The resulting, detected NMR signal is much stronger in comparison to conventional NMR. Signal enhancements of 300 times and more have previously been reported. DNP has enabled rapid spectroscopy of molecules where NMR is not possible or obtaining the spectrum would take a very long time and several medical applications have also been outlined.
Despite the benefits and popularity of DNP in the NMR community, the understanding of the mechanisms driving DNP is not yet complete. Following the work, and success of numerous groups worldwide, I am working to contribute to the theory of DNP.
My aim is to construct theoretical models, which are to provide an insight into the physics of DNP. Quantum mechanical formulations of different relaxation mechanisms will be analysed, and their impact on the dynamics of spin polarisation investigated. In particular, many-body system simulations are of interest. It is hoped that these can provide new information on DNP dynamics, and transport of polarization to atomic nuclei; both those surrounding the electron, and ones further from it.
Simple model systems consisting of several coupled spins will be extended to simulations involving many interacting spins. Models will be constructed for Solid Effect, Cross Effect, and Thermal Mixing mechanisms of DNP. The ultimate goal is to develop realistic models that can fit and explain experimental data.
Recent work focuses on the Solid Effect. Following a suitable projection method, under reasonable circumstances, the polarization dynamics were shown to be contained in the Zeeman subspace. Using a Lindblad master equation restricted to the named subspace enables quantum mechanical simulations of systems greater in size than any previously studied. However, this space restriction also enables the use of efficient Dynamic Monte Carlo (DMC) algorithms, which further increases the number of spins that can be simulated. DMC simulations involving up to 1331 spins have successfully been carried out.
Conferences, workshops and visits
March 2013 - visit at Dartmouth College, Hanover, NH, USA. One hour talk given on the "Effective Master Equation for Solid Effect Dynamic Nuclear Polarization".
March 2014 - 55th ENC conference, Westin Waterfront Hotel, Boston, MA, USA. Poster no. 397 - "Simululating Solid Effect Dynamic Nuclear Polarization using Dynamic Monte Carlo". Awarded the Student Travel Stipend to cover costs associated with travelling to the conference site.
April 2014 - visit at Dartmouth College, Hanover, NH, USA. One hour talk given on the "Solid Effect Simulations using Dynamic Monte Carlo - Simulating large systems in Hilbert space".
April 2014 - IMR-CDT Advanced Workshop II. University of Dundee, Dundee, UK. Poster on "Simululating Solid Effect Dynamic Nuclear Polarization using Dynamic Monte Carlo - a novel approach for large systems".
April 2014 - Third meeting of the QUAINT coordination action on Optimal Control of Quantum Systems, Sandbjerg Estate, Denmark. Poster on "Simululating Solid Effect Dynamic Nuclear Polarization using Dynamic Monte Carlo - a novel approach for large systems". Twenty minute talk given on "Solid Effect Simulations using Dynamic Monte Carlo - Simulating large systems in Hilbert space".
January 2015 - Quantum Cybernetics & Control workshop at Nottingham University, Nottingham UK. Presented poster on "Large spin system simulations of Dynamic Nuclear Polarization using Dynamic Monte Carlo in Hilbert space".
April 2015 - IMR-CDT Advanced Workshop III. University of Warwick, Warwick, UK. Oral presentation on "Simulating Dynamic Nuclear Polarization using Dynamic Monte Carlo".
April 2015 - 56th ENC conference, Asilomar Conference Suite, Asilomar, CA, USA. Poster no. 149 - "Simulating Cross Effect Dynamic Nuclear Polarization using Dynamic Monte Carlo".
August/September 2015 - 5th DNP Symposium, Hotel Zuiderduin, Egmond Aan Zee, Netherlands. Oral presentation on "Simulating Dynamic Nuclear Polarization using Dynamic Monte Carlo".
Publications
A. Karabanov, D. Wisniewski, I. Lesanovsky, W. Kockenberger, “Dynamic nuclear polarization as kinetically constrained diffusion”, Phys. Rev. Lett., Vol. 115, 020404 (2015).
D. Wisniewski, A. Karabanov, I. Lesanovsky, W. Kockenberger, "Solid effect DNP polarization dynamics in a system of many spins", J. Magn. Reson., Vol. 264, 30-38 (2016).