Summary
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 September 2022
Group Photo September 2019
Group Photo March 2019
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