Gerhard
C. Hegerfeldt
Work Address:
Institut für Theoretische Physik
der Universität Göttingen
Friedrich-Hund-Platz 1
D-37077 Göttingen
Phone: ++49 551 39-7676
Fax: ++49 551 39-9263
E-Mail: Gerhard.Hegerfeldt@physik.uni-goettingen.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:
- On the ocean-beach - why elliptic pebbles do not become
spherical (with K. Winzer),
Eur Phys. J. Plus
94 (2021), 136:671.
- Time-optimal quantum control of nonlinear two-level systems (with
X. Chen and Y.Ban),
Phys. Rev. A 94 (2016), 023624.
- High-speed driving of a two-level system, Phys. Rev. A 90 (2014), 032110.
- Driving at the quantum speed limit: Optimal control of a two-level
system, Phys. Rev. Lett. 111 (2013), 260501.
- Discriminating between the von Neumann and Lüders reduction
rule (with R. Salo-Mayato), 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 Aharonov-Bohm 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
-
Passage-time distributions from a spin-boson 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, spread-out particles (with J. T. Neumann und L. S. Schulman), J. of Physics A39 (2006), 14447 - 14463
- Scattering of two-level 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 dipole-dipole 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 time-of-arrival model in three dimensions (with V. Hannstein, J. G. Muga), J. Phys. B: At. Mol. Opt. Phys 38 , (2005), 409-420
- 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) 063002-1 - 063002-4
- Exact and approximate complex potentials for modelling time
observables (with A. Ruschhaupt, J. A. Damborenea, B. Navarro, J. G.
Muga) Europhys. Letters 67 1-7 (2004)
- Cooperative quantum jumps for three dipole-interacting atoms (with
V. Hannstein), Phys. Rev. A 70,
023820
- Operator-normalized 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 dipole-dipole
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 time-of-arrival 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 measurement-based 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, 245-251 (2002)
- Matter-Wave-Diffraction 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), 357-363 (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 dipole-interacting
atoms (with S. U. Addicks, A. Beige, M. Dakna), Eur. Phys. J. D15,
393-404 (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, 2284-2287 (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 Atom-Optical State-Selection Technique, Phys. Rev. Lett. 84,
15-3219 (2000) (with T. Köhler)
- Deviations from classical optics in matter diffraction and
determination of the size of weakly bound molecules, Phys. Rev. 61,236061-2360610
(1999)(with T. Köhler)
- Determination of Atom-Surface van der Waals Potentials from
Transmission-Grating Diffraction Intensities, Phys. Rev. Lett. 83,
1755-1759 (with R.E. Grisenti, W. Schöllkopf, J.P. Toennies, T.
Köhler)
- Cooperative effects in the light and dark periods of two
dipole-interacting atoms. Phys. Rev. A59, 2385-2391 (1999) (with
A. Beige)
- Few-Body Approach to Diffraction of Small Helium Clusters by
Nanostructures. Few-Body Systems Suppl. 10, 263-272 (1999) (with
T. Köhler)
- Instantaneous spreading and Einstein causality in quantum
theory.
Ann. d. Phys. 7, 716-725 (1998)
- Ensemble versus individual system in quantum optics. Fortschr.
Phys. 46, 595-604 (1998)
- Transition from antibunching to bunching for two
dipole-interacting atoms. Phys. Rev. A58, 4133-4139 (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. 238-245 (1998)
- Atomic versus molecular diffraction: Influence of break-ups and
finite size, Phys. Rev. A 57, 2021-2029 (1998) (with T.
Köhler)
- Unusual light spectra from a two-level atom in squeezed vacuum,
Quantum Semiclass. Opt. 9, 1-13 (1997) (with T.I. Sachse und
D.G.
Sondermann)
- Atomic Quantum Zeno Effect for Ensembles and Single Systems,
Found. Phys. 27, 1671-1688 (1997) (with A. Beige, D.G.
Sondermann)
- Quantum Zeno Effect and Light-Dark Periods, J. Phys. A: Math.
Gen. 30, 1323-1334 (1997) (with A. Beige)
- State Measurements with Short Laser Pulses and Lower-Efficiency
Photon Detectors, J. Mod. Opt. 44, 345-357 (1997) (with A.
Beige)
- Laser Pulses as Measurements: Applications to the Quantum Zeno
Effect, Quantum Semiclass Opt. 8, 999-1015 (1996)(with A. Beige
and D.G. Sondermann)
- Conditional Hamiltonian and Reset Operator in the Quantum Jump
Approach, Quantum Semiclass. Opt. 8, 121-132 (1996) (with
D.G. Sondermann)
- Conditional resonance-fluorescence spectra of single atoms,
Phys.
Rev. A 53, 1164-1178 (1996) (with M.B. Plenio)
- Projection Postulate and Atomic Quantum Zeno Effect, Phys. Rev.
A 53,
53-65 (1996) (with A. Beige)
- Spectral structures induced by electron shelving, Phys. Rev. A 52,
3333-3343 (1995) (with M.B. Plenio)
- Dark periods in a single radiating Lambda-System, Z. Phys. B
96, 533-539 (1995) (with M.B. Plenio)
- Quantum beats revisited: a quantum jump approach, Quantum Opt. 6,
15-25 (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,
3531-3540 (1994) (with R. Henneberg)
- Problems about Causality in Fermi's Two-Atom Model and Possible
Resolutions, in: Nonlinear, Deformed and Irreversible Quantum Systems,
ed. by H.-D. Doebner, World Scientific, Singapore (1995), p. 253-264
(with V.K. Dobrev, P. Nattermann)
- Causality Problems for Fermi's Two-Atom System. Phys. Rev. Lett 72,
596-599 (1994)
- Coherence with incoherent light: A new type of quantum beats for
a single atom. Phys. Rev. A 47 (1993), p. 2186-2189 (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. 104-115 (with
T.S. Wilser)
- A Quantum Characterization of Gaussianness. In: Quantum
Probability and Related Topics, Vol. VII, L. Accardi Ed., World
Scientific, 1992, pp. 165-173
- Novel Quantization Phenomenon for Relativistic Wave Equations.
Phys. Rev. D 45 (1992), 713-716 (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. 75-83
- Quantum Chaos in Hydrogen, Phys. Rev. A 41 (1990),
1161-1164 (Rapid Communication, with R. Henneberg)
- Laser Cooling in Ion Traps: Noncooling of a Transverse
Component.
Phys. Rev. A 41 (1990), 2610-2613 (with A. Vogt)
- Difficulties with Causality in Particle Localization. Nuclear
Physics B (Proc. Suppl.) {\bf 6} (1989) 231-237
- Density Expansions for the Auto-Correlation Function of
Spectral-Line Profiles, Phys. Rev. A 39 (1989), 3609-3617 (with
H. Schulze)
- Quantum Shot Noise: Expansions in Powers of the Pulse
Density. J. Statist. Phys. 51 (1988), 711-738 (with H. Schulze)
- Noncommutative Cumulants for Stochastic Differential
Equations and for Generalized Dyson Series. J. Stat. Phys.
{\bf 51} (1988), 691-710 (with H. Schulze)
- Collision-Time Simulation Technique for
Pressure-Broadened Spectral Lines with Applications to Ly-$\alpha$,
Phys. Rev. A37 (1988), 1488-96 (with V. Kesting)
- New Classical Properties of Quantum Coherent States. J. Math.
Phys. 27 (1986), 2731-37 (with G.G. Emch)
- Violation of Causality in Relativistic Quantum Theory?
Phys. Rev. Lett.54 (1985), 2395-2398
- Noncommutative Analogs of Probabilistic Notions and
Results. J. Funct. Analysis 64 (1985), 436-456
- A Noncommutative Marcinkiewicz Theorem, Publ. Res. Inst.
Math. Sci. (Kyoto)21 (1985), 191-204 (with
K. Baumann)
- Factors of the Fock Functional. J. Math. Phys. 26
(1985), 62-64
- Inequalities of Schwarz and Hölder Type for Random
Operators. J. Math. Phys. 26 (1985), 1576-77
- Stochastic Aspects in the Theory of Spectral-Line
Broadening. II. Noncommutative Cluster Expansions. J. Statistical
Phys.32 (1983), 337-360 (with R. Reibold)
- Stochastic Aspects in the Theory of Spectral-Line
Broadening. I. Collision Time Statistics and N-Perturber Liwith,
J. Statistical Phys. 32 (1983), 313-335 (with
R. Reibold)
- A New Formula for the Spectral-Line Broadening in Plasmas
with Applications to the Asymmetry of Ly-$\alpha$, Z. Naturforsch.
37a (1982), 305-315 (with R. Reibold)
- Moment Inequalities and Statistical Constraints with
Applications to Turbulence Experiments, Phys. Lett. 86A (1981),
1-4 (with G. Sandri)
- The Asymptotic Fall-Off of a Stark-Broadened Spectral Line
in the Classical Path Model, Phys. Lett. 82A (1981), 340-344 (with R. Reibold)
- Remarks on Causality, Localization, and Spreading of Wave
Packets, Phys. Rev. D22 (1980), 377-384 (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. 149-165
- Correlation Inequalities for Ising Ferromagnets with
Symmetries, Commun. Math. Phys. 57 (1977), 259-266
- Mixing Properties in Lattice Systems, Commun. Math. Phys.
53 (1977), 1-7 (with C.R. Nappi)
- Is the Wick-Square Infinitely Divisible? J. Math. Phys.
18 (1977), 171-172 (with K. Baumann)
- Prime Field Decompositions and Infinitely Divisible States
on Borchers' Tensor Algebra, Commun. Math. Phys. 45 (1975),
137-152
- Extremal Decomposition of Wightman Functions and of States
on Nuclear *-Algebras by Choquet Theory, Commun. Math. Phys. 45
(1975), 133-136
- Remark on Causality and Particle Localization, Phys. Rev.
D10 (1974), 3320-21
- Probability Measures on Distribution Spaces and Quantum
Field Theoretical Models, Rep. Math. Phys. 7 (1975), 99-105
- Functional Characterization of Markov Fields and Examples
of Non-Markovian Euclidean Fields. Il Nuovo Cim. 25B (1975),
538-545
- From Euclidean to Relativistic Fields and on the Notion of
Markoff Fields. Commun. Math. Phys. 35 (1974), 155-171
- Field Product Renormalization and Wilson-Zimmermann
Expansion in a Class of Euclidean Invariant Models. Il Nuovo Cim.
19A (1974), 153-172 (with J.R. Klauder)
- Smoothing Operators for Field Domains. J. Math. Phys. 15 (1974), 621-624
-
Über ein Problem der Relativitätstheorie: Wann sind
Punktbildungen des $R^n$ linear? Nachr. Akad. Wiss. Göttingen, Jahrgang 1972,
205-229 (with H.J. Borchers)
-
The structure of space-time 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), 257-267
- The Ultralocal Model: Fields without Partners. Acta Phys.
Austr. Suppl. IX (1972), 856-859 (with J.R. Klauder)
- Fields without Partners. Nuovo Cim. A10 (1972),
723-738 (with J.R. Klauder)
- Gårding Domains and Analytic Vectors for Quantum
Fields. J. Math. Phys. 13 (1972), 821-827
- On Canonical Commutation Relations and
Infinite-Dimensional Measures. J. Math. Phys. 13 (1972), 45-50
- Decomposition into Irreducible Representations for the
Canonical Commutation Relations. Nuovo Cim. B4 (1971), 225-244
- Equivalence of Basis-Dependent and Basis-Independent
Approach to Canonical Field Operators. J. Math. Phys. 12
(1971), 167-172
- Metrics on Test Function Spaces for Canonical Field
Operators. Commun. Math. Phys. 16 (1970), 329-346 (with J.R.
Klauder)
- The Form of Representations of the Canonical Commutation
Relations for infinitely many
Degrees of Freedom. Commun. Math. Phys. 12 (1969), 304-323 (with
O. Melsheimer)
- Kernel Integral Formulas for the Canonical Commutation
Relations of Quantum Fields. II. Irreducible Representations. J.
Math. Phys. 11 (1970), 21-29
- Kernel Integral Formulas for the Canonical Commutation
Relations of Quantum Fields. I. Representations with Cyclic Field. J.
Math. Phys. 10 (1969), 1681-1698
- Aspekte der kanonischen Vertauschungsrelationen für
Quantenfelder. Habilitationsschrift, Marburg 1968, 100 S.
- Proof of the Fermion Superselection Rule without the
Assumption of Time Reversal Invariance. J. Math. Phys. 9
(1968), 2029-2031 (with K. Kraus und E.P. Wigner)
- Coupling of Space-Time and Internal Symmetry. Fortschr.
Phys. 16 (1968), 491-544 (with J. Henning)
- Critical Remark on the Observability of the Sign Change of
Spinors under 2$\pi$-Rotations. Phys. Rev. 170 (1968),
1185-1186 (with K. Kraus)
- Note on Poincareé Group Extensions and Internal Symmetry
Transformations. Nucl. Phys. B3 (1967), 189-191 (with K. Kraus)
- Some Properties of a Class of Generalized Inonü-Wigner
Contractions. Nuovo Cim. 51 (1967), 439-447
- Branching Theorem for the Symplectic Groups. J. Math. Phys.
8 (1967), 1195-1196
- Applications of a Unique Group Embedding: Spin Extensions
for $G_2$ and the Sp(6)-Trion-Model. Z. Phys. 199 (1967),
369-377 (with H.D. Doebner)
- Group embedding of Space-Time and Internal Symmetry Groups.
J. Math. Phys. 8 (1967), 730-741 (with H.D. Doebner)
- Spin and Lorentz Extensions of Intrinsic Symmetry Groups.
Acta Phys. Austr. Suppl. III (1966), 369-379 (with H.D. Doebner)
- Über eine Methode zur Konstruktion von Spin- und
Lorentz-Extensionen innerer Symmetriegruppen. Dissertation, Marburg
1965, 87 S.
- One-Particle Singularities and SU(3). Ann. d. Phys.
7 , Bd. 15 (1965), 412-414 (with H. D. Doebner)
- Remarks on $\omega - \phi$ and Octet-Octet Mixing. Nuovo
Cim. 33 (1964), 1724-1727 (with H.D. Doebner)