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• (Fall) PHYS 205. Engineering Physics I: Mechanics.
  (Spring) PHYS 206. Engineering Physics II: Electricity and Magnetism.
  Class--MWF 10:00-10:50 AM, Simperman 314
  Lab Sections (all in Simperman 121):

Wednesday	Thursday
11:00 AM - 12:50 PM (A)
3:00 - 4:50 PM (B)	3:45 - 5:35 PM (C)

General Information
Syllabus

• ENGR/PHYS 305. Electronics & Circuit Analysis I.
  Class--MWF 2:00-2:50 PM, Simperman 106
  Lab Sections (all in Simperman 120):

Monday

11:00 AM - 12:50 PM (A)

3:00-4:50 PM (B)

General Information
Syllabus

Background:

Education:

	Cornell University Ph.D., Applied Physics (1985) Thesis Title: "Domain Wall Interactions and Spatially Modulated Phases" Thesis Advisor: Dr. Michael E. Fisher M.Sc., Applied Physics (with Mathematics Minor) (1983)
	University of Cambridge Certificate of Post-Graduate Study in Natural Science (1980) Thesis Title: "Electrical and Optical Properties of Thin Films of Group IV Amorphous Semiconductors prepared in Ultra-high Vacuum and measured in situ"
	Princeton University B.S.Eng., Electrical Engineering (Engineering Physics Program) (1979)

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Employment:

• Carroll College, Helena, Montana, 1993-present
  Department of Natural Sciences
  Associate Professor, 1995-present
  Assistant Professor, 1993-1995
• St. John's University, Collegeville, Minnesota, 1990-1993
  Department of Physics
  Assistant Professor (limited-term appointment)
• University of Utah, Salt Lake City, Utah, 1987-1989
  Department of Physics
  Post-doctoral appointment
• Corporate Research & Development Center, General Electric Company, Schenectady, New York, 1985-1987
  Materials Laboratory
  Staff Research appointment

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Selected Publications:

1. "Optical Constants and D.C. Electrical Conductivity of Evaporated Films of Amorphous Germanium" (with P. Viscor), Kinam 3, 365-388 (1981).

2. "D.C. Electrical Conductivity of Evaporated Amorphous Germanium--the Low-Temperature Behavior" (with P. Viscor), Philosophical Magazine B45, 485-496 (1982).

3. "Melting and Wetting Transitions in the Three-State Chiral Clock Model" (with D.A. Huse and M.E. Fisher), Physica 121A, 363-398 (1983).

4. "The Asymptotic Behaviour of Directed Self-Avoiding Walks," Journal of Physics A16, 2883-2885 (1983).

5. "Finite-Size Scaling for Directed Self-Avoiding Walks" (with V. Privman), Physical Review B28, 6613-6615 (1983); 29, 5224(E) (1984).

6. "Low-Temperature Phase Diagram of the ANNNI Model in a Magnetic Field," Journal of Physics C18, 569-579 (1985).

7. "Monte Carlo Study of a Model for the Roughening Transition of High-Index Crystal Faces" (with W. Selke), Zeitschrift für Physik B62, 381-386 (1986).

8. "Domain Wall Interactions and Spatially Modulated Phases" (with M.E. Fisher), Physical Review Letters 57, 1044-1047 (1986).

9. "Domain Wall Interactions I. General Features and Phase Diagrams for Spatially Modulated Phases" (with M.E. Fisher), Physical Review B36, 644-666 (1987).

10. "Domain Wall Interactions II. High-Order Phases in the ANNNI Model" (with M.E. Fisher), Physical Review B36, 5343-5362 (1987).

11. "Domain Wall Interactions III. High-Order Phases in the Three-State Chiral Clock Model" (with M.E. Fisher), Physical Review B36, 5363-5376 (1987).

12. "Integer Quantized Hall Effect in Spin-Density-Wave Phases of Two-Dimensional Conductors" (with M. Kohmoto), University of Tokyo ISSP Report Ser. A, No. 2109 (1989).

13. "Review and Theory of Oxygen Ordering in the High-Temperature Superconductor YBa₂Cu₃O_7-x" (with M.L. Glasser, D.C. Mattis, and M.P. Mattis), Phase Transitions 22, 185-211 (1990).

14. "Structural Mechanics--Beams and Bridges" (with J.L. Scharf), in Interdisciplinary Lively Application Projects (ILAPs), ed. David C. Arney (Mathematical Association of America, 1997), pp. 143-159.

15. "Classroom Strategies for Cooperative Learning" (with W.E. Fenton et al.), in Cooperative Learning in Undergraduate Mathematics: Issues that Matter and Strategies that Work, MAA Notes # 55, ed. E.C. Rogers et al. (Mathematical Association of America, 2001), Chapter 3 (pp. 23-53).

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Research Topics:

University of Utah (Salt Lake City, Utah, 1987-1989)

• Integer Quantized Hall Effect
  Integer quantization of the Hall conductivity in the spin-density-wave ordered phases of two-dimensional organic conductors was modeled by a tight-binding Hamiltonian. It was discovered that the conductivity--a topological invariant determined by zeros of the electron wave-function in the magnetic Brillouin zone--can change both in magnitude and sign under variation of the spin-density-wave amplitude, as pairs of zeros coalesce and mutually annihilate (see publication 12).
• Oxygen Ordering in High-Temperature Superconductors
  The basal-plane ordering of oxygen into Cu-O chains, which characterizes the tetragonal-orthorhombic structural transition in the high-temperature superconductor YBa₂Cu₃O_7-x, was studied. Two-dimensional Ising lattice gas models, in mean-field approximation, were shown to be capable of accounting for the observed transition temperature only if a change in average oxygen valence from O^- in the tetragonal phase to O^2- in the orthorhombic phase is posited (see publication 13).

Institut für Festkörperforschung der Kernforschungsanlage Jülich
(Jülich, Germany, 1985)

• Surface Roughening Transitions
  The possible roughening transition of metallic surfaces [the high-index (11n) faces of fcc crystals] was studied by Monte Carlo simulation of a simple terrace-step-kink model. Comparison was made with data from He beam diffraction experiments on Cu surfaces (see publication 7).

Cornell University (Ithaca, New York, 1982-1985)

• Domain Wall Interactions in Spatially Modulated Phases
  A general theoretical framework was developed to study the thermodynamics of spatially modulated materials which exhibit ordered domains in a uniaxial array. Examples include magnetic phases of rare-earth alloys, structural polytypes of ternary alloys, ferroelectric insulators, and graphite intercalates. Specific features of low-temperature phase diagrams for three-dimensional systems, including the possibility of a novel quasi-tricritical point on the commensurate-incommensurate phase boundary, were identified as consequences of the (n = 2, 3, ...)-body interactions, W_n, among the domain walls (see publications 8 and 9). Analytic calculation of these W_n, and hence asymptotically exact low-temperature phase diagrams, were obtained for two discrete spin lattice models--the axial next-nearest-neighbor Ising (ANNNI) and the three-state chiral clock (CC₃) models--by a transfer matrix method. Extension of the calculations to the mean-field limit of infinite interlayer coordination number showed that mean-field theory predicts a qualitatively incorrect phase diagram for the CC₃ model, even in the limit of vanishingly small temperature (see publications 8, 10, and 11).
• Melting and Wetting Transitions and Random Walk Models in Two Dimensions
  For models in two dimensions, the nature of melting and wetting transitions was studied by numerical analysis (e.g., Padé approximants) of series expansions for basic thermodynamic quantities, and by exploiting formal correspondences between domain walls and random walks (see publication 3). Generating-function techniques were used to probe additional properties of simple random-walk models (see publications 4 and 5) including, in particular, an anomalous type of finite-size scaling (see publication 5).

University of Cambridge (Cambridge, England, 1979-1980)

• Transport Properties of Thin Amorphous Semiconductor Films
  Thin films of amorphous Ge were prepared, and their electrical and optical transport properties measured at 20-300 K under ultra-high vacuum. The magnitude and detailed temperature dependence of the electrical conductivity were successfully described by a nearest-neighbor hopping model expanded to include all strengths of electron-phonon coupling and both acoustic and optical phonon modes (see publications 1 and 2).

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Current Interests:

Interdisciplinary Lively Application Projects (ILAPs)

Cooperative Learning in Undergraduate Mathematics (CLUME)

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