Willem H. Dickhoff

Willem H. Dickhoff

​Professor of Physics
PhD, Free University in Amsterdam
research interests:
  • Quantum Many-Body Problem
  • Nuclei at the Limits of Stability
  • Nuclear Matter
  • Pairing in Neutron Stars

contact info:

office hours:

  • By appointment
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mailing address:

  • Washington University
    MSC 1105-109-03
    One Brookings Drive
    St. Louis, MO 63130-4899

Professor Dickhoff's research concentrates mostly on the solution of the nuclear many-body problem. He teaches undergraduate and graduate courses in quantum mechanics, nuclear and particle physics.

Dickhoff has contributed to a quantitative understanding of the role of correlations beyond the mean-field in determining the properties of nucleons in the ground states of nuclei with closed shells near the valley of stability. He is currently engaged in studying the role of such correlations when climbing up the valley to the proton and neutron drip lines where nuclei are studied, which may only occur in supernova explosions in nature. Some of these nuclei can now be studied at new facilities in the US, Japan, Germany, and France. Due to the possibility for large differences between the number of protons and neutrons, such systems are also of particular interest for the study of neutron stars. Dickhoff has co-authored a textbook together with Dimitri Van Neck from the University of Ghent, Belgium, now in its second edition, entitled Many-Body Theory Exposed! - Propagator Description of Quantum Mechanics in Many-Body Systems.

With colleagues from Spain, England, Germany, and Belgium, as well as participation of several graduate students and the occasional post-doc, his group attempts to answer the fundamental science question: How do the properties of protons and neutrons in the nucleus change from the valley of stability to the respective drip lines? Since new experimental information relies on strongly interacting probes this also means that the group is engaged in improving the description of nuclear reactions by utilizing the dispersive optical model (DOM).

The phase diagram of the matter of nuclei is presumed known at extremely high density and low temperatures, and low density and high temperature. At high temperature and small chemical potential, quark-gluon plasma with unusual properties provides the correct description. Less well understood is the phase diagram of nucleonic matter around densities corresponding to the interior of heavy nuclei and its critical dependence on nucleon asymmetry. The corresponding science question also studied in the group therefore reads: What is the phase diagram of the nucleonic matter as a function of density, temperature, and isospin with emphasis on superfluidity or superconductivity and its relevance for neutron stars.

Professional History

Professor Dickhoff received his "Kandidaats" (BSc) in 1974, "Doctoraal" (MSc) in 1977, and PhD in 1981 from the Free University in Amsterdam. The title of his thesis was "The particle-hole interaction and pion condensation." During his doctoral studies he spent the first year at the Institut für Kernphysik in Jülich, Germany. After his thesis defense he moved to Tübingen, Germany, for four years of postdoctoral research. After one year at TRIUMF on the campus of UBC in Vancouver he moved to St. Louis and became assistant professor in the Washington University physics department in 1986. Since 1997 he is a full professor. He recently was elected a Fellow of the American Physical Society.

recent courses

Quantum Theory of Many-Particle Systems (Physics 540)

Develops a modern approach to quantitative microscopic description of strongly-interacting quantum many-particle systems, including the helium liquids, nuclear matter, neutron star matter, nuclei, and strongly-coupled electron systems. Emphasis is placed on the method of self-consistent Green's functions. Diagram resumption and field theoretic techniques are introduced. Applications are discussed that cover the Hartree-Fock method for atoms, Bose-Einstein condensation of atoms, etc. The microscopic basis for pairing in superfluids and superconductors is also examined.

    Physics of Finite and Infinite Nuclear Systems (Physics 477/542)

    Quantum mechanics of finite and infinite systems of protons and neutrons. Independent-particle model of nuclei and shell structure. Contrast with atomic shell model. Isospin symmetry. Information from weakly and strongly interacting probes of nuclei. Nuclear decay properties and some historical context. Many-particle description of nuclear systems. Single-particle versus collective phenomena. Properties of excited states. Bulk properties of nuclei. Nuclear and neutron matter. Role of different energy scales in determining nuclear properties: influence of long-range, short-range, and medium-induced interactions. Pairing correlations in nuclear systems. Relevance of nuclear phenomena and experiments for astrophysics and particle physics. Prerequisites: Phys 318 or Phys 471, or permission of instructor

      Quantum Mechanics (Physics 471)

      Origins of quantum theory, wave packets and uncertainty relations, Schroedinger's equation in one dimension, step potentials and harmonic oscillators, eigenfunctions and eigenvalues, Schroedinger's equation in three dimensions, the hydrogen atom, symmetry, spin and the periodic table, approximation methods for time-independent problems, quantum statistics.

        Quantum Mechanics I (Physics 523)

        Provides a rigorous introduction to quantum mechanics with an emphasis on formalism. The course begins with review of the theory of linear (state) vector spaces and the quantum theory of measurement. Topics covered include dynamics of quantized systems and the quantum theory of angular momentum.