# Niels Gronbech-Jensen

Web Page: http://www.math.ucdavis.edu/~ngjensen/

Email: ngjensen@math.ucdavis.edu

Office: MSB 3212

Phone: 530-752-5335

### Research

Niels Grønbech-Jensen studies the dynamics and statistics of nonlinear physical systems through analytical and numerical techniques. Much of the work is connected to collaborations with a variety of applied physics objectives. He is also a Professor in the Department of Mechanical and Aerospace Engineering at UC Davis.

Examples of research interests include classical Molecular Dynamics in the context of atomic and molecular descriptions of soft matter (e.g., bio-membranes and molecular self-assembly) as well as hard matter (e.g., radiation damage in crystals). He is also engaged in the development and analysis of new numerical algorithms for efficient and accurate discrete-time modeling of equations of motion with thermal noise. Another interest is a thorough investigation of the driven-damped pendulum equation with a present emphasis on the dynamics of superconducting (Josephson) tunnel junctions. A specific goal is to understand if the quantum interpretation of experimentally observed macroscopic behavior of Josephson devices is exclusive or if classical dynamics of nonlinear oscillators can equally well explain the observed phenomena.

Grønbech-Jensen is educated at the Technical University of Denmark with a degree in Applied Mathematical Physics (M.Sc. [Cand.] 1989, "Squeezed States of Light") and Physics (Ph.D. [Lic.] 1991, "Phase-locked excitations in the sine-Gordon and related systems"). After a postdoctoral research position in Applied Physics at Stanford University, where he was introduced to biomolecular simulations, he spent seven years in the Theoretical Division at Los Alamos National Laboratory, working on atomic and molecular scale materials modeling, high-performance computing, solitons and phase-locking in nonlinear systems, and numerical algorithm development, before coming to UC Davis in 1999 as Professor of Applied Science and Faculty Scientist at Lawrence Berkeley National Laboratory.

### Selected *Publications*

- Tomography and entanglement in coupled Josephson junction qubits, Niels Grønbech-Jensen, Jeffrey E. Marchese, Matteo Cirillo, and James A. Blackburn Physical Review Letters 105, 010501 (2010).
- Molecular simulation analysis of structural variations in lipoplexes, Oded Farago and Niels Grønbech-Jensen Soft Matter 7, 4302 (2011).
- A simple and effective Verlet-type algorithm for simulating Langevin dynamics, Niels Grønbech-Jensen and Oded Farago Molecular Physics 111, 983 (2013).
- A survey of classical and quantum interpretations of experiments on Josephson junctions at very low temperatures, James A. Blackburn, Matteo Cirillo, and Niels Grønbech-Jensen Physics Reports 611, 1 (2016).
- Accurate configurational and kinetic statistics in discrete-time Langevin systems, Lucas Frese Grønbech Jensen and Niels Grønbech-Jensen Molecular Physics 117, 2511 (2019).
- Complete set of stochastic Verlet-type thermostats for correct Langevin simulations, Niels Grønbech-Jensen Molecular Physics 118, e1662506 (2020).

### Honors and Awards

- Fellow of The American Physical Societ, elected 2010
- R&D 100 Award (R&D Magazine), 1999
- Outstanding Teaching Award, Department of Physics & Astronomy, University of California, Los Angeles, 1996/1997
- Gordon Bell Prize, Honorable Mention, IEEE Computer Society, 1993
- Los Alamos National Lab Director's Postdoctoral Fellow, 1992-1994

*Last updated: 2021-09-14*