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Dynamics of irradiation in materials and biological systems
Most Recent Publication
Electron-phonon thermalization in a scalable method for real-time quantum dynamics, Physical Review B, 2016, 93, No. 2
doi: 10.1103/PhysRevB.93.024306 Abstract Full Text
We present a quantum simulation method that follows the dynamics of out-of-equilibrium many-body systems of electrons and oscillators in real time. Its cost is linear in the number of oscillators and it can probe time scales from attoseconds to hundreds of picoseconds. Contrary to Ehrenfest dynamics, it can thermalize starting from a variety of initial conditions, including electronic population inversion. While an electronic temperature can be defined in terms of a nonequilibrium entropy, a Fermi-Dirac distribution in general emerges only after thermalization. These results can be used to construct a kinetic model of electron-phonon equilibration based on the explicit quantum dynamics.
Matter under irradiation undergoes structural changes. Two examples are radiation damage in nuclear reactors and strand breaks in DNA. Radiation damage involves a system-dependent sequence of processes, with a key common element: an energy source (light, high-velocity ions) excites electrons; they transport and deposit charge and energy through the material, inducing atomic dynamics and changes in chemical bonding in distant regions. This is a hard problem in non-adiabatic electron-nuclear dynamics. In this project we wish to develop an idea for tractable quantum electron-ion dynamics and combine it with fist principles electronic-structure theory, to model inelastic electron transport in materials and biomolecules.