Gerhard
C. Hegerfeldt
Work Address:
Institut für Theoretische Physik
der Universität Göttingen
FriedrichHundPlatz 1
D37077 Göttingen
Phone: ++49 551 397676
Fax: ++49 551 399263
EMail: Gerhard.Hegerfeldt@physik.unigoettingen.de
__________________________________________________________________________________________________________________
Biographical Sketch:
G. C. Hegerfeldt studied Physics and Mathematics at the universities
of Kiel, Cambridge (UK) and Marburg, where he obtained his diploma
doctorate and Habilitation at the institute of G. Ludwig. He has worked
on quantum field theory, on causality questions on statistical physics
of spectral line broadening, and more recently on quantum optics
("quantum jump approach") and on atom optics (diffraction of "matter
waves" and of extended molecules). He was visiting fellow at
Princeton University in the year 1979/80, at the California Institute
of
Technology in Pasadena in the year 1984/85 and a member of the
Institute for Advanced study in Princeton in the year 1989/90.
Research Interests:
Publications:
 Timeoptimal quantum control of nonlinear twolevel systems,
Phys. Rev. A 94 (2016), 023624.
 Highspeed driving of a twolevel system, Phys. Rev. A 90 (2014), 032110.
 Driving at the quantum speed limit: Optimal control of a twolevel
system, Phys. Rev. Lett. 111 (2013), 260501.
 Discriminating between the von Neumann and Lüders reduction
rule (with R. SaloMayato), Phys. Rev. A 85 (2013), 032116.
 Symmetries and time operators (with J. G. Muga), J. Phys. A: Math. Theor. 43 (2010), 505303.
 Manufacturing time operators: Covariance, selection criteria,
and examples (with J. G. Muga), Phys. Rev. A 82 (2010), 012113.
 The quantum jump approach and some of its applications, Lect. Notes Phys. 789 (2009), 127  174.
 Detector models for the quantum time of arrival (with A. Ruschhaupt and J. G. Muga), Lect. Notes Phys. 789 (2009), 65  96.
 The AharonovBohm effect: the role of tunneling and associated forces (with J. T. Neumann), J. Phys. A: Math. Theor. 41 (2008), 155305.

How to measure the wave function absolute squared of a moving
particle by using mirrors (with V. Hannstein)
, Europhys. Letters 77 (2007), 60003

Passagetime distributions from a spinboson detector model (with J. T. Neumann, L. S. Schulman), Phys. Rev. A 75 (2007), 012108

Comment on Evolution in Time of Moving Unstable Systems, Concepts of Physics III (2006), 207  210
 Investigation of a quantum mechanical detector model for moving, spreadout particles (with J. T. Neumann und L. S. Schulman), J. of Physics A39 (2006), 14447  14463
 Scattering of twolevel atoms by delta lasers: Exactly solvable models in atom optics (with D. Seidel und J. G. Muga), J. Phys. B: At. Mol. Opt. Phys. 39 (2006), 4673  4682
 Simplified approach to double jumps for fluorescing dipoledipole interacting atoms (with V. Hannstein), Eur. Phys. J. D. 38 , (2006), 415 (Highlight Paper)
 Time development of single quantum systems In: Group Theoretical Methods in Physics, Inst. of Physics Conference Series Number 185, Ed. by George S. Pogosyan, Luis Edgar Vicent and Kurt Bernardo Wolf, Institute of Physics Publishing(IOP), Bristol and Philadelphia (2005), 299  304
 Quantum optical timeofarrival model in three dimensions (with V. Hannstein, J. G. Muga), J. Phys. B: At. Mol. Opt. Phys 38 , (2005), 409420
 Matter Wave Diffraction from an Inclined Transmission Grating: Searching for the Elusive 4He Trimer Efimov State (with R. Brühl, A. Kalinin, O. Kornilov, J. P. Toennies, M. Stoll) Phys. Rev. Letters 95 (2005) 0630021  0630024
 Exact and approximate complex potentials for modelling time
observables (with A. Ruschhaupt, J. A. Damborenea, B. Navarro, J. G.
Muga) Europhys. Letters 67 17 (2004)
 Cooperative quantum jumps for three dipoleinteracting atoms (with
V. Hannstein), Phys. Rev. A 70,
023820
 Operatornormalized quantum arrival times in the presence of
interactions (with D. Seidel, J. G. Muga, B. Navarro), Phys. Rev. A 70, 012110 (2004)
 Cooperative fluorescence effects for dipoledipole
interacting systems with experimentally relevant level configurations
(with V. Hannstein), Phys. Rev. A 68,
043826 (2003)
 Blinking Molecules: Determination of photophysical parameters
from the intensity correlation function (with Seidel), J. of Chem. Phys.
118, 7741 (2003)
 The
Quantum Jump Approach and Quantum Trajectories,
Springer LNP 622: Irreversible
Quantum Dynamics, F. Benatti, R. Floreanini Eds., p. 233  242
(2003)
 On atomic timeofarrival measurements with a laser of finite
beam width (with J. A. Damborenea, I. L. Egusquiza, J. G. Muga), J.
Phys. B: At. Mol. Opt. Phys., 36,
2657  2669 (2003)
 Optimal atomic detection of ultracold atoms by control of
detuning and spatial dependence of laser intensity (with I. L.
Egusquiza, J. G. Muga, B. Navarro), J. Phys., B: At. Mol. Opt. Phys. 36, 3899  3907 (2003)
 Suppression of Rabi oscillations for moving atoms (with I. L.
Egusquiza, J. G. Muga, B. Navarro), Phys. Ref. A 67, 063819 (2003)
 Quantum arrival times and operator normalization (with J. G. Muga,
D. Seidel), Phys. Rev. A 68,
022111 (2003)
 A measurementbased approach to quantum arrical times
(with J. A. Damborenea, I. L. Egusaquiza, J. G. Muga), Phys.
Rev. A 66, 502104 (2002)
 The intensity correlation function of "blinking" quantum systems
(with D. Seidel), Quantum Semicl. Opt. 4, 245251 (2002)
 MatterWaveDiffraction off Nano Gratings: Quantum Effects,
Proceeding of th XXII Solvy Conference, to appear.
 The van der Waals Potential between Metastable Atoms and Solid
Surfaces: Novel Diffraction Experiments versus Theory, Eur. Phys. Lett.
59 (3), 357363 (2002) (with R. Brühl, P. Fouquet, R. E. Grisenti,
J. P. Toennies, T. Köhler, M. Stoll, C. Walter)
 Particle localization and the notion of Einstein causality, in: Extensions
of Quantum Theory 3, Eds. A. Horzela and E. Kapuscik, Apeiron,
Montreal (2001), p. 9  16
 Double jumps and transition rates for two dipoleinteracting
atoms (with S. U. Addicks, A. Beige, M. Dakna), Eur. Phys. J. D15,
393404 (2001)
 Quantentheorie der Materiewellenbeugung, Physikalisches
Blätter 56, Heft 11, p. 53  55(2000) (with R. E. Grisenti,
T. Köhler, J. P. Toennies)
 Determination of the Bond Length and Binding Energy of the
Helium Dimer by Diffraction from a Transmission Grating, Phys.
Rev. Lett. 85, 22842287 (2000) (with R. E. Grisenti, W.
Schöllkopf, J. P. Toennies, T. Köhler, M. Stoll)
 How to study the Elusive Efimov State of the 4He3 Molecule
through a New AtomOptical StateSelection Technique, Phys. Rev. Lett. 84,
153219 (2000) (with T. Köhler)
 Deviations from classical optics in matter diffraction and
determination of the size of weakly bound molecules, Phys. Rev. 61,2360612360610
(1999)(with T. Köhler)
 Determination of AtomSurface van der Waals Potentials from
TransmissionGrating Diffraction Intensities, Phys. Rev. Lett. 83,
17551759 (with R.E. Grisenti, W. Schöllkopf, J.P. Toennies, T.
Köhler)
 Cooperative effects in the light and dark periods of two
dipoleinteracting atoms. Phys. Rev. A59, 23852391 (1999) (with
A. Beige)
 FewBody Approach to Diffraction of Small Helium Clusters by
Nanostructures. FewBody Systems Suppl. 10, 263272 (1999) (with
T. Köhler)
 Instantaneous spreading and Einstein causality in quantum
theory.
Ann. d. Phys. 7, 716725 (1998)
 Ensemble versus individual system in quantum optics. Fortschr.
Phys. 46, 595604 (1998)
 Transition from antibunching to bunching for two
dipoleinteracting atoms. Phys. Rev. A58, 41334139 (1998) (with
A. Beige)
 Causality, Particle Localization and
Positivity of the Energy in
quantum theory, in: Irreversibility and Causality edited by A.
Bohm, H.D. Doebner, and P. Kielanowski. Lecture Notes in Physics 504,
p. 238245 (1998)
 Atomic versus molecular diffraction: Influence of breakups and
finite size, Phys. Rev. A 57, 20212029 (1998) (with T.
Köhler)
 Unusual light spectra from a twolevel atom in squeezed vacuum,
Quantum Semiclass. Opt. 9, 113 (1997) (with T.I. Sachse und
D.G.
Sondermann)
 Atomic Quantum Zeno Effect for Ensembles and Single Systems,
Found. Phys. 27, 16711688 (1997) (with A. Beige, D.G.
Sondermann)
 Quantum Zeno Effect and LightDark Periods, J. Phys. A: Math.
Gen. 30, 13231334 (1997) (with A. Beige)
 State Measurements with Short Laser Pulses and LowerEfficiency
Photon Detectors, J. Mod. Opt. 44, 345357 (1997) (with A.
Beige)
 Laser Pulses as Measurements: Applications to the Quantum Zeno
Effect, Quantum Semiclass Opt. 8, 9991015 (1996)(with A. Beige
and D.G. Sondermann)
 Conditional Hamiltonian and Reset Operator in the Quantum Jump
Approach, Quantum Semiclass. Opt. 8, 121132 (1996) (with
D.G. Sondermann)
 Conditional resonancefluorescence spectra of single atoms,
Phys.
Rev. A 53, 11641178 (1996) (with M.B. Plenio)
 Projection Postulate and Atomic Quantum Zeno Effect, Phys. Rev.
A 53,
5365 (1996) (with A. Beige)
 Spectral structures induced by electron shelving, Phys. Rev. A 52,
33333343 (1995) (with M.B. Plenio)
 Dark periods in a single radiating LambdaSystem, Z. Phys. B
96, 533539 (1995) (with M.B. Plenio)
 Quantum beats revisited: a quantum jump approach, Quantum Opt. 6,
1525 (1994) (with M.B. Plenio)
 Level statistics for continuous energy spectra with application
to hydrogen atom in crossed electric and magnetic fields, Phys. Rev. A 49,
35313540 (1994) (with R. Henneberg)
 Problems about Causality in Fermi's TwoAtom Model and Possible
Resolutions, in: Nonlinear, Deformed and Irreversible Quantum Systems,
ed. by H.D. Doebner, World Scientific, Singapore (1995), p. 253264
(with V.K. Dobrev, P. Nattermann)
 Causality Problems for Fermi's TwoAtom System. Phys. Rev. Lett 72,
596599 (1994)
 Coherence with incoherent light: A new type of quantum beats for
a single atom. Phys. Rev. A 47 (1993), p. 21862189 (with M.B.
Plenio)
 How to reset an atom after a photon detection. Applications to
photon counting processes. Phys. Rev. A 47 (1993), 449
 Macroscopic dark periods without metastable state. Phys. Rev. A
46, 373 (1992) (with M.B. Plenio)
 Ensemble or Individual System,
Collapse or no Collapse: A
Description of a Single Radiating Atom, in: Classical and Quantum
Systems, Proc. II. International Wigner Symposium, Goslar 1991, H.D.
Doebner, W.
Scherer, and F. Schroeck, Eds., World Scientific 1992; p. 104115 (with
T.S. Wilser)
 A Quantum Characterization of Gaussianness. In: Quantum
Probability and Related Topics, Vol. VII, L. Accardi Ed., World
Scientific, 1992, pp. 165173
 Novel Quantization Phenomenon for Relativistic Wave Equations.
Phys. Rev. D 45 (1992), 713716 (with M.K. Hinders, B.A. Rhodes,
and
G. v. H. Sandri)
 An Alternative Approach to the Quantization of Linear
Relativistic Field Equations. Lecture Notes in Physics 379, J.D.
Hennig,
W. Lücke, J. Tolar, Eds., Springer 1991, p. 7583
 Quantum Chaos in Hydrogen, Phys. Rev. A 41 (1990),
11611164 (Rapid Communication, with R. Henneberg)
 Laser Cooling in Ion Traps: Noncooling of a Transverse
Component.
Phys. Rev. A 41 (1990), 26102613 (with A. Vogt)
 Difficulties with Causality in Particle Localization. Nuclear
Physics B (Proc. Suppl.) {\bf 6} (1989) 231237
 Density Expansions for the AutoCorrelation Function of
SpectralLine Profiles, Phys. Rev. A 39 (1989), 36093617 (with
H. Schulze)
 Quantum Shot Noise: Expansions in Powers of the Pulse
Density. J. Statist. Phys. 51 (1988), 711738 (with H. Schulze)
 Noncommutative Cumulants for Stochastic Differential
Equations and for Generalized Dyson Series. J. Stat. Phys.
{\bf 51} (1988), 691710 (with H. Schulze)
 CollisionTime Simulation Technique for
PressureBroadened Spectral Lines with Applications to Ly$\alpha$,
Phys. Rev. A37 (1988), 148896 (with V. Kesting)
 New Classical Properties of Quantum Coherent States. J. Math.
Phys. 27 (1986), 273137 (with G.G. Emch)
 Violation of Causality in Relativistic Quantum Theory?
Phys. Rev. Lett.54 (1985), 23952398
 Noncommutative Analogs of Probabilistic Notions and
Results. J. Funct. Analysis 64 (1985), 436456
 A Noncommutative Marcinkiewicz Theorem, Publ. Res. Inst.
Math. Sci. (Kyoto)21 (1985), 191204 (with
K. Baumann)
 Factors of the Fock Functional. J. Math. Phys. 26
(1985), 6264
 Inequalities of Schwarz and Hölder Type for Random
Operators. J. Math. Phys. 26 (1985), 157677
 Stochastic Aspects in the Theory of SpectralLine
Broadening. II. Noncommutative Cluster Expansions. J. Statistical
Phys.32 (1983), 337360 (with R. Reibold)
 Stochastic Aspects in the Theory of SpectralLine
Broadening. I. Collision Time Statistics and NPerturber Liwith,
J. Statistical Phys. 32 (1983), 313335 (with
R. Reibold)
 A New Formula for the SpectralLine Broadening in Plasmas
with Applications to the Asymmetry of Ly$\alpha$, Z. Naturforsch.
37a (1982), 305315 (with R. Reibold)
 Moment Inequalities and Statistical Constraints with
Applications to Turbulence Experiments, Phys. Lett. 86A (1981),
14 (with G. Sandri)
 The Asymptotic FallOff of a StarkBroadened Spectral Line
in the Classical Path Model, Phys. Lett. 82A (1981), 340344 (with R. Reibold)
 Remarks on Causality, Localization, and Spreading of Wave
Packets, Phys. Rev. D22 (1980), 377384 (with S.N. Ruijsenaars)
 Representations of the Canonical Commutation Relations of
Quantum Field Theory. In: Functional Analysis: Surveys and Results
II. K.D. Bierstedt and B. Fuchssteiner (eds.). North Holland Publ.
Co., 1979, p. 149165
 Correlation Inequalities for Ising Ferromagnets with
Symmetries, Commun. Math. Phys. 57 (1977), 259266
 Mixing Properties in Lattice Systems, Commun. Math. Phys.
53 (1977), 17 (with C.R. Nappi)
 Is the WickSquare Infinitely Divisible? J. Math. Phys.
18 (1977), 171172 (with K. Baumann)
 Prime Field Decompositions and Infinitely Divisible States
on Borchers' Tensor Algebra, Commun. Math. Phys. 45 (1975),
137152
 Extremal Decomposition of Wightman Functions and of States
on Nuclear *Algebras by Choquet Theory, Commun. Math. Phys. 45
(1975), 133136
 Remark on Causality and Particle Localization, Phys. Rev.
D10 (1974), 332021
 Probability Measures on Distribution Spaces and Quantum
Field Theoretical Models, Rep. Math. Phys. 7 (1975), 99105
 Functional Characterization of Markov Fields and Examples
of NonMarkovian Euclidean Fields. Il Nuovo Cim. 25B (1975),
538545
 From Euclidean to Relativistic Fields and on the Notion of
Markoff Fields. Commun. Math. Phys. 35 (1974), 155171
 Field Product Renormalization and WilsonZimmermann
Expansion in a Class of Euclidean Invariant Models. Il Nuovo Cim.
19A (1974), 153172 (with J.R. Klauder)
 Smoothing Operators for Field Domains. J. Math. Phys. 15 (1974), 621624

Über ein Problem der Relativitätstheorie: Wann sind
Punktbildungen des $R^n$ linear? Nachr. Akad. Wiss. Göttingen, Jahrgang 1972,
205229 (with H.J. Borchers)

The structure of spacetime transformations,
Commun. math. Phys. 28,(1972) 259  266 (with H. J. Borchers)

The Lorentz Transformations: Derivation of Linearity and
Scale Factor. Nuovo Cim. A10 (1972), 257267
 The Ultralocal Model: Fields without Partners. Acta Phys.
Austr. Suppl. IX (1972), 856859 (with J.R. Klauder)
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723738 (with J.R. Klauder)
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Fields. J. Math. Phys. 13 (1972), 821827
 On Canonical Commutation Relations and
InfiniteDimensional Measures. J. Math. Phys. 13 (1972), 4550
 Decomposition into Irreducible Representations for the
Canonical Commutation Relations. Nuovo Cim. B4 (1971), 225244
 Equivalence of BasisDependent and BasisIndependent
Approach to Canonical Field Operators. J. Math. Phys. 12
(1971), 167172
 Metrics on Test Function Spaces for Canonical Field
Operators. Commun. Math. Phys. 16 (1970), 329346 (with J.R.
Klauder)
 The Form of Representations of the Canonical Commutation
Relations for infinitely many
Degrees of Freedom. Commun. Math. Phys. 12 (1969), 304323 (with
O. Melsheimer)
 Kernel Integral Formulas for the Canonical Commutation
Relations of Quantum Fields. II. Irreducible Representations. J.
Math. Phys. 11 (1970), 2129
 Kernel Integral Formulas for the Canonical Commutation
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 Coupling of SpaceTime and Internal Symmetry. Fortschr.
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 Critical Remark on the Observability of the Sign Change of
Spinors under 2$\pi$Rotations. Phys. Rev. 170 (1968),
11851186 (with K. Kraus)
 Note on Poincareé Group Extensions and Internal Symmetry
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 Some Properties of a Class of Generalized InonüWigner
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 Branching Theorem for the Symplectic Groups. J. Math. Phys.
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 Applications of a Unique Group Embedding: Spin Extensions
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369377 (with H.D. Doebner)
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