Imperial College London


Faculty of Natural SciencesDepartment of Mathematics

Royal Society University Research Fellow (Reader)



+44 (0)20 7594 8549e.graefe CV




6M35Huxley BuildingSouth Kensington Campus





I am a Royal Society University Research Fellow and proleptic Reader in the Mathematical Physics Group. My research background is in theoretical quantum physics in the context of atomic physics, and in particular the description of ultracold atoms and Bose-Einstein condensates.

My research group is working on theoretical quantum dynamics. We are investigating quantum-classical correspondence of open quantum systems described by non-Hermitian (and often PT-symmetric) Hamiltonians or Lindblad equations. We aim to develop a semiclassical framework for these theories and understand the quantum signatures of chaos. Some of us are also interested in quantum transition rate theories. We like to think our ideas are useful in cold atoms, optics, materials, and other applications.

group photo on queens lawn

Group Photo September 2022

Group photo on Queens lawn

Group Photo September 2019

Group Photo March 2019

Group Photo March 2019

group photo September 2018

Group photo - September 2018

Selected Publications

Journal Articles

Graefe E-M, Schubert R, Christie R, et al., 2022, Quantum-jump vs stochastic Schrödinger dynamics for Gaussian states with quadratic Hamiltonians and linear Lindbladians, Journal of Physics A - Mathematical and Theoretical, Vol:55, ISSN:1751-8113, Pages:1-31

Graefe E-M, Malzard S, Melanathuru VR, 2022, Landau-Zener transitions through a pair of higher order exceptional points, Physical Review A, Vol:106, ISSN:1050-2947, Pages:1-11

Mudute-Ndumbe S, Graefe E-M, 2020, Quantum chaos in a non-Hermitian PT-symmetric kicked top, New Journal of Physics, Vol:22, ISSN:1367-2630

Longstaff B, Graefe E-M, 2020, Bloch oscillations in a Bose-Hubbard chain with single-particle losses, Journal of Physics B - Atomic Molecular and Optical Physics, Vol:53, ISSN:0953-4075, Pages:1-13

Longstaff B, Graefe E-M, 2019, Non-adiabatic transitions through exceptional points in the band structure of a PT-symmetric lattice, Physical Review A: Atomic, Molecular and Optical Physics

Graefe EM, Longstaff B, Plastow T, et al., 2018, Lindblad dynamics of Gaussian states and their superpositions in the semiclassical limit, Journal of Physics A - Mathematical and Theoretical, Vol:51, ISSN:1751-8113

Graefe EM, Korsch HJ, Rush A, 2016, Quasiclassical analysis of Bloch oscillations in non-Hermitian tight-binding lattices, New Journal of Physics, Vol:18, ISSN:1367-2630

Graefe E-M, Rush A, Schubert R, 2016, Propagation of Gaussian beams in the presence of gain and loss, Ieee Journal of Selected Topics in Quantum Electronics, Vol:22, ISSN:1558-4542

Graefe E-M, Mudute-Ndumbe S, Taylor M, 2015, Random matrix ensembles for PT-symmetric systems, Journal of Physics A - Mathematical and Theoretical, Vol:48, ISSN:1751-8113

Graefe E-M, Graney M, Rush A, 2015, Semiclassical quantization for a bosonic atom-molecule conversion system, Physical Review A: General Physics, Vol:92, ISSN:0556-2791

Graefe E-M, Korsch HJ, Rush A, et al., 2014, Classical and quantum dynamics in the (non-Hermitian) Swanson oscillator, Journal of Physics A-mathematical and General, ISSN:1361-6447

Graefe E-M, Mailybaev AA, Moiseyev N, 2013, Breakdown of adiabatic transfer of light in waveguides in the presence of absorption, Physical Review A, Vol:88, ISSN:1050-2947

Brody DC, Graefe E-M, 2012, Mixed-State Evolution in the Presence of Gain and Loss, Physical Review Letters, Vol:109, ISSN:0031-9007

Graefe E-M, 2012, Stationary states of a <i>PT</i> symmetric two-mode Bose-Einstein condensate, Journal of Physics A - Mathematical and Theoretical, Vol:45, ISSN:1751-8113

Graefe E-M, Schubert R, 2012, Complexified coherent states and quantum evolution with non-Hermitian Hamiltonians, Journal of Physics A - Mathematical and Theoretical, Vol:45, ISSN:1751-8113

Demange G, Graefe E-M, 2012, Signatures of three coalescing eigenfunctions, Journal of Physics A - Mathematical and Theoretical, Vol:45, ISSN:1751-8113

Brody DC, Graefe E-M, 2011, Six-dimensional space-time from quaternionic quantum mechanics, Physical Review D, Vol:84, ISSN:1550-7998

Graefe E-M, Jones HF, 2011, PT-symmetric sinusoidal optical lattices at the symmetry-breaking threshold, Physical Review A, Vol:84, ISSN:1050-2947

Graefe E-M, Schubert R, 2011, Wave-packet evolution in non-Hermitian quantum systems, Physical Review A, Vol:83, ISSN:1050-2947

Graefe E-M, Hoening M, Korsch HJ, 2010, Classical limit of non-Hermitian quantum dynamics-a generalized canonical structure, Journal of Physics A - Mathematical and Theoretical, Vol:43, ISSN:1751-8113

Graefe E, Korsch HJ, Niederle AE, 2010, Quantum Classical Correspondence for a non-Hermitian Bose-Hubbard Dimer, Phys. Rev. A, Vol:82

Brody DC, Graefe EM, 2010, Coherent states and rational surfaces, J Phys A-math Theor, Vol:43

Graefe EM, Korsch HJ, Niederle AE, 2008, Mean-Field Dynamics of a Non-Hermitian Bose-Hubbard Dimer, Physical Review Letters, Vol:101, ISSN:0031-9007

Graefe EM, Guenther U, Korsch HJ, et al., 2008, A non-Hermitian PT symmetric Bose-Hubbard model:: eigenvalue rings from unfolding higher-order exceptional points, Journal of Physics A - Mathematical and Theoretical, Vol:41, ISSN:1751-8113

Strzys MP, Graefe EM, Korsch HJ, 2008, Kicked Bose-Hubbard systems and kicked tops - destruction and stimulation of tunneling, New Journal of Physics, Vol:10, ISSN:1367-2630

Graefe EM, Korsch HJ, 2007, Semiclassical quantization of an <i>N</i>-particle Bose-Hubbard model, Physical Review A, Vol:76, ISSN:1050-2947

Witthaut D, Graefe EM, Korsch HJ, 2006, Towards a generalized Landau-Zener formula for an interacting Bose-Einstein condensate in a two-level system, Physical Review A, Vol:73, ISSN:1050-2947

Graefe EM, Korsch HJ, Witthaut D, 2006, Mean-field dynamics of a Bose-Einstein condensate in a time-dependent triple-well trap: Nonlinear eigenstates, Landau-Zener models, and stimulated Raman adiabatic passage, Physical Review A, Vol:73, ISSN:2469-9926

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