Dr Keith Hughes

My area of research is theoretical and concentrates on the quantum dynamical aspect of molecular processes. Motivation for this work is driven by the desire to gain deep insight and understanding of molecular behaviour at the most detailed level. I am involved with the development of new theoretical and computational methods in quantum dynamics, and in the application of these methods to key areas of chemical interest, such as:

• Charge and energy transfer in materials and biological systems
• Solvation dynamics

Quantum dynamics in large complex environments

The quantum dynamics of large complex molecular systems on an ultrafast (femtosecond) timescale necessitates the use of reduced non-Markovian master equations or else an explicit treatment of the molecular sub-system and environment is required. We use the recently developed hierarchical effective-mode approach (see publications list) to study the quantum dynamics of complex molecular systems. The approach enables an accurate representation of the sytem-environment dynamics to be constructed and allows for more controlled approximations to the system-environment description to be made. The method has wide range of applications including energy transfer in DNA, gas-surface processes and charge and energy transfer processes in materials such as organic devices.  

Example: Non-Markovian reduced dynamics of ultrafast charge transfer at an oligothiophene-fullerene heterojunction, K. H. Hughesm, B. Cahier, R. Martinazzo, H. Tamura and I. Burghardt, Chem. Phys. 442, 111, (2014). (FEMTO 11 special issue) DOI: 10.1016/j.chemphys.2014.06.015

Mixed quantum-classical approach to non-equilibrium solvation

Attention here is focussed on the development of a mesoscopic mixed quantum-classical description of non-equilibrium solvation that goes beyond the dynamical density functional theory (DDFT) level. The method is applicable for studying a wide range of transport and solvation processes. Quantum coherence effects are fully captured by the approach, making it suitable for studying long-lived coherences in large biological systems, for example, excitation energy transfer in photosynthetic systems.

I am willing to supervise a PhD

2019

• PublishedVibronic coupling models for donor-acceptor aggregates using an effective-mode scheme: Application to mixed Frenkel and charge-transfer excitons in oligothiophene aggregates
  Hughes, K., Burghardt, I., Wjatscheslaw, P., Polkehn, M. & Martinazzo, R., 28 Jun 2019, In : Journal of Chemical Physics. 150, 24, 244114.
  Research output: Contribution to journal › Article

2015

• PublishedQuantum dynamics of hydrogen atoms on graphene. I. System-bath modeling
  Bonfanti, M., Jackson, B., Hughes, K. H., Burghardt, I. & Martinazzo, R., 23 Sep 2015, In : Journal of Chemical Physics. 143, 124703
  Research output: Contribution to journal › Article
• PublishedQuantum dynamics of hydrogen atoms on graphene. II. Sticking
  Bonfanti, M., Jackson, B., Hughes, K. H., Burghardt, I. & Martinazzo, R., 23 Sep 2015, In : Journal of Chemical Physics. 143, 1124704
  Research output: Contribution to journal › Article
• PublishedVibrational relaxation and decoherence in structured environments: a numerical investigation
  Bonfanti, M., Hughes, K. H., Burghardt, I. & Martinazzo, R., 3 Jul 2015, In : Annalen der Physik.
  Research output: Contribution to journal › Article

2014

• PublishedNon-Markovian reduced dynamics of ultrafast charge transfer at an oligothiophene–fullerene heterojunction
  Hughes, K. H., Cahier, B., Martinazzo, R., Tamura, H. & Burghardt, I., 9 Jul 2014, In : Chemical Physics. 442, p. 111-118
  Research output: Contribution to journal › Article

2012

• PublishedNon-Markovian reduced dynamics based upon a hierarchical effective-mode representation
  Burghardt, I., Matinazzo, R. & Hughes, K. H., 12 Oct 2012, In : Journal of Chemical Physics. 137, 14, p. Article 144107
  Research output: Contribution to journal › Article
• PublishedCompact MCTDH Wave Functions for High-Dimensional System-Bath Quantum Dynamics
  Bonfanti, M., Tantardini, G. F., Hughes, K. H., Martinazzo, R. & Burghardt, I., 4 Sep 2012, In : Journal of Physical Chemistry C. 116, 46, p. 11406-11413
  Research output: Contribution to journal › Article
• PublishedMaximum-entropy closure of hydrodynamic moment hierarchies including correlations
  Hughes, K. H. & Burghardt, I., 7 Jun 2012, In : Journal of Chemical Physics. 136, 21, p. Article 214109
  Research output: Contribution to journal › Article
• PublishedExtended hydrodynamic approach to quantum-classical nonequilibrium evolution. II. Application to nonpolar solvation
  Hughes, K. H., Baxter, S., Bousquet, D., Ramanathan, P. & Burghardt, I., 7 Jan 2012, In : Journal of Chemical Physics. 136, 1, 014102.
  Research output: Contribution to journal › Article

2011

• PublishedUnraveling a Brownian particle’s memory with effective mode chains
  Martinazzo, R., Hughes, K. H. & Burghardt, I., 14 Sep 2011, In : Physical Review E. 84, 3, p. Article 030102
  Research output: Contribution to journal › Article
• PublishedExtended hydrodynamic approach to quantum-classical nonequilibrium evolution. I. Theory
  Bousquet, D., Hughes, K. H., Micha, D. A. & Burghardt, I., 11 Feb 2011, In : Journal of Chemical Physics. 134, 6, p. Article 064116
  Research output: Contribution to journal › Article
• PublishedUniversal Markovian reduction of Brownian particle dynamics.
  Martinazzo, R., Vacchini, B., Hughes, K. H. & Burghardt, I., 7 Jan 2011, In : Journal of Chemical Physics. 134, 1, p. 011101
  Research output: Contribution to journal › Article

2010

• PublishedEffective spectral densities for system-environment dynamics at conical intersections: S2-S1 conical intersection in pyrazine.
  Martinazzo, R., Hughes, K. H., Martelli, F. & Burghardt, I., 25 Nov 2010, In : Chemical Physics. 377, 1-3, p. 21-29
  Research output: Contribution to journal › Article
• PublishedA hybrid hydrodynamic lliouvillian approach to non-Markovian dynamics.
  Hughes, K. H., Burghardt, I. & Chattaraj, P. (ed.), 1 Jan 2010, Quantum Trajectories. 2010 ed. Taylor and Francis
  Research output: Chapter in Book/Report/Conference proceeding › Chapter

2009

• PublishedEffective-mode representation of non-Markovian dynamics: A hierarchical approximation of the spectral density. II. Application to environment-induced nonadiabatic dynamics.
  Hughes, K. H., Christ, C. D. & Burghardt, I., 28 Sep 2009, In : Journal of Chemical Physics. 131, 12, p. 124108
  Research output: Contribution to journal › Article
• PublishedEffective-mode representation of non-Markovian dynamics: A hierarchical approximation of the spectral density. I. Application to single surface dynamics.
  Hughes, K. H., Christ, C. D. & Burghardt, I., 14 Jul 2009, In : Journal of Chemical Physics. 131, 2, p. 024109
  Research output: Contribution to journal › Article
• PublishedClosure of quantum hydrodynamic moment equations.
  Hughes, K. H., Parry, S. M. & Burghardt, I., 7 Feb 2009, In : Journal of Chemical Physics. 130, 5, p. 054115
  Research output: Contribution to journal › Article
• PublishedQuantum hydrodynamics for mixed states.
  Hughes, K. H., Parry, S. M., Burghardt, I., Shalashilin, D. V. (ed.) & De Miranda, M. P. (ed.), 1 Jan 2009, Multidimensional Quantum Mechanics with Trajectories. 2009 ed. CCP, Daresbury, p. 74-76
  Research output: Chapter in Book/Report/Conference proceeding › Chapter

2007

• PublishedA hybrid hydrodynamic-liouvillian approach to mixed quantum-classical dynamics: application to tunneling in a double well
  Hughes, K. H., Parry, S. M., Parlant, G. & Burghardt, I., 1 Aug 2007, In : Journal of Physical Chemistry A. 111, 41, p. 10269-10283
  Research output: Contribution to journal › Article
• PublishedQuantum hydrodynamics and a new approach to mixed quantum-classical theory.
  Burghardt, I., Moller, K. B., Hughes, K. H. & Micha, D. A. (ed.), 1 Jan 2007, Quantum Dynamics of Complex Molecular Systems. 2007 ed. Springer, p. 391-422
  Research output: Chapter in Book/Report/Conference proceeding › Chapter

2006

• PublishedDynamics of Open Quantum Systems
  Hughes, K. H. (ed.), 1 Jan 2006, 2006 ed. CCP, Daresbury.
  Research output: Book/Report › Book
• PublishedOptical control of dissipative quantum phase space dynamics.
  Hughes, K. H., Hywel. M.*, N. V., Lasorne, B. (ed.) & Worth, G. A. (ed.), 1 Jan 2006, Coherent Control of Molecules. 2006 ed. CCP, Daresbury, p. 28-33
  Research output: Chapter in Book/Report/Conference proceeding › Chapter

2005

• PublishedDissipative quantum phase space dynamics on dynamically adapting grids.
  Hughes, K. H., 1 Feb 2005, In : Journal of Chemical Physics. 122, 7, p. 074106-074117
  Research output: Contribution to journal › Article

2004

• PublishedTrajectory approach to dissipative quantum phase space dynamics: application to barrier scattering
  Hughes, K. H. & Wyatt, R. E., 1 Mar 2004, In : Journal of Chemical Physics. 120, 9, p. 4089-4097
  Research output: Contribution to journal › Article

2003

• PublishedA new method for wave packet dynamics: derivative propagation along quantum trajectories
  Trahan, C. J., Hughes, K. H. & Wyatt, R. E., 1 Jan 2003, In : Journal of Chemical Physics. 118, 22, p. 9911
  Research output: Contribution to journal › Article
• PublishedTorsion-rotation interactions in monodeuterated acetaldehyde
  Cox, A. P., Hughes, K. H. & Macdonald, J., 1 Jan 2003, In : Molecular Physics. 101, 4-5, p. 569-574
  Research output: Contribution to journal › Article
• PublishedWavepacket dynamics on arbitrary Lagrangian-Eulerian grids: application to an Eckart barrier
  Hughes, K. H. & Wyatt, R. E., 1 Jan 2003, In : Physical Chemistry Chemical Physics. 5, 18, p. 3905-3910
  Research output: Contribution to journal › Article

2002

• PublishedWavepacket dynamics on dynamically adapting grids: application of the equidistribution principle
  Hughes, K. H. & Wyatt, R. E., 10 Dec 2002, In : Chemical Physics Letters. 366, 3-4, p. 336-342
  Research output: Contribution to journal › Article

2000

• PublishedBoltzmann wavepacket dynamics on periodic molecular potential functions.
  Hughes, K. H. & Macdonald, J. N., 1 Oct 2000, In : Physical Chemistry Chemical Physics. 2, 19, p. 4267-4273
  Research output: Contribution to journal › Article
• PublishedBoltzmann wavepacket dynamics of tunnelling of molecules through symmetric and asymmetric energy barriers on non-periodic potential functions.
  Hughes, K. H. & Macdonald, J. N., 1 Aug 2000, In : Physical Chemistry Chemical Physics. 2, 16, p. 3539-3547
  Research output: Contribution to journal › Article