Dr. Brad Trees

Richardson-Linebaugh Professor

Department of Physics and Astronomy

Ohio Wesleyan University

Delaware, OH 43015

Office: Conrades-Weatherall Science Center (CWSC):  139

Phone: 740-368-3776

Chair: Ohio Section/American Physical Society

E-mail

SPECIAL NEWS: RESEARCH EXPERIENCE FOR TEACHERS OPPORTUNITY AVAILABLE: MORE INFORMATION AT THE REU/RET WEBSITE, OR READ THIS FLYER.

Research Activities and Funding:  

  • Dynamics of Josephson Junction Arrays: phase-locking/synchronization in arrays of Josephson junctions.  

  • Nano- and micromechanical oscillators: candidates for qubits when coupled with Josephson junctions.

  • Funding: National Science Foundation, Research Experience for Undergraduates and Teachers, REU/RET. Read more about this grant at our special REU site.

  • Publications (* denotes an undergraduate coauthor):

  • "Suppression of macrosopic quantum tunneling in a large Josephson junction coupled to a resonator," Brad R. Trees, Yaser H. Helal* (Ohio Wesleyan University), Joshua S. Schiffrin* (Carnegie Mellon Univerisity), and Brian M. Siller* (former OWU student, now at the University of Illinois at Urbana-Champaign), Physical Review B, vol 76, article number 224513 (2007).
  • "Nanomechanical-resonator-induced synchronization in Josephson junction arrays," B. R. Trees, S. Natu*, and D. Stroud, Physical Review B, vol 72, article number 214524 (2005).
  • ibid, Virtual Journal of Applications of Superconductivity,  Jan. 1, 2006. (Chosen to appear by editor.)
  • "Synchronization in disordered Josephson junction arrays: small-world connections and the Kuramoto model," B. R. Trees, V. Saranathan*, and D. Stroud, Physical Review E, vol 71, article number 016215 (2005).
  • ibid, Virtual Journal of Applications of Superconductivity, Jan. 15, 2005. (Chosen to appear by editor.)
  • "Synchronization of coupled rotators: Josephson junction ladders and the locally-coupled Kuramoto model," B. C. Daniels*, S. T. M. Dissanayake*, and B. R. Trees, Physical Review E, vol  67, article number 026216 (2003).
  • ibid, Virtual Journal of Applications of Superconductivity, vol 4, issue 5, 2003. (Chosen to appear by editor.)
  • "Phase locking in Josephson junction arrays: a review of recent theoretical work," B. R. Trees,  in Studies of High Temperature Superconductors, vol. 39, edited by A. Narlikar (NOVA Science Publishers, Hungtinton NY, 2002).
  • "Phase locking in Josephson ladders and the discrete sine-Gordon equation:  the effects of boundary conditions and current induced magnetic fields," B. R. Trees and R. A. Murgescu*, Physical Review E, vol. 64, article number 46205, 2001.
  • "Instabilities in Josephson ladders with current induced magnetic fields," B.R. Trees and R. A. Murgescu*,  Physical Review B, vol 63, article number 144503, 2001.
  • "Floquet exponents of underdamped Josephson ladders: a comparison with predictions of the discrete sine-Gordon equation," B. R. Trees and N. Hussain*, Physical Review E, vol 61, 2000, pp. 6415-6425.
  • "Two-dimensional arrays of Josephson junctions in a magnetic field: a stability analysis of synchronized states," B. R. Trees and D. Stroud, Physical Review B, vol 59, 1999, pp. 7108-7115.
  • "Linear arrays of Josephson junctions: a stability analysis of characteristic modes," B. R. Trees and E. B. Harris, Physical Review B, vol 57, 1998, pp. 5425-5431.
  • "Multiplet effects in the quasiparticle band structure of the f 1 -f2 Anderson model," B. R. Trees, A. J.  Fedro, and M. Norman, Physical Review B, vol 51 (1995), pp. 6167-6170.
  • "A superconducting instability in the infinite-U Anderson lattice in the presence of crystal electric fields," B. R. Trees, Physical Review B, vol 51 (1995), pp. 470-488.
  • "Quasiparticle interactions in the Anderson lattice:  effects of crystalline anisotropy," B. R. Trees and D. L. Cox, Physical Review B, vol 49 (1994), pp. 16066-16069.
  • "Model of Nuclear Relaxation in YBa2Cu3O7-x ," D. L. Cox and B. R. Trees, Physical  Review B, vol 41 (1990), pp. 11260-11270.

Invited and Contributed Talks by me or my students

  • March Meeting Talk, 2008: "Suppression of Macrosopic Quantum Tunneling in a Large Josephson Junction Coupled to a Resonator,". (Clink the link to see a pdf file of the talk: Talk Slides.)

  • "Synchronization of Coupled Junction-Resonator System," given by S. Natu, October 2005 meeting of the Ohio Section of the American Physical Society, Cleveland State University, Cleveland, Ohio.
  • "Synchronization in Josephson Junction Arrays: The Kuramoto Model and Small World Networks," given by B. R. Trees at Ohio Northern University, Department of Physics colloquium, January 5, 2005.
  • " Synchronization in Disordered Josephson Junction Arrays," given by B. R. Trees at group meeting of Professor John Wilkins, Department of Physics, The Ohio State University, May 26, 2004.
  • "Effects of Small-World Connections on Synchronization in Disordered Josephson Junction Arrays," given by B. R. Trees, March 2004 meeting of the American Physical Society, Montreal, Canada.
  • "Synchronized Tunneling: the Curious Dynamics of Josephson Junction Arrays," April 2003 at Kenyon College.
  • "Synchronization in Disordered Josephson Junction Arrays," given by B. C. Daniels, October 2002 meeting of the American Physical Society, The Ohio State University, Columbus, Ohio.
  • "Synchronization in Disordered Josephson Ladder Arrays ," given by B. R. Trees, March 2002 meeting of the American Physical Society, Indianapolis, Indiana.
  • "Synchronization in Disordered Josephson Junction  Arrays," given by S. T. M. Dissanayake, October 2001 meeting of the Ohio Section of the American Physical Society, Columbus State Community College, Columbus, Ohio.
  • "Instabilites in Josephson ladders with current induced magnetic fields," given by R. A. Murgescu, October 2000, Ohio Section meeting of the American Physical Society, University of  Toledo.
  • "Phase locking in Josephson junction arrays:  A stability analysis," October 1999, invited seminar for the Department of Physics at Ball State University.
  • "Two-dimensional arrays of Josephson junctions in a magnetic field: A stability analysis of synchronized states," March 1999, Centennial Meeting of the American Physical Society, Atlanta GA.
  • "Linear arrays of Josephson junctions:  A stability analysis of characteristic modes," October 1997, Ohio Section meeting of the American Physical Society, Miami University.
  • "Quasiparticle pairing instabilities in the Anderson lattice: Effects of crystalline anisotropy," March 1994, meeting of the American Physical Society, Pittsburgh PA.
  • "Effects of crystal fields on quasiparticle interactions in the infinite-U Anderson lattice," September 1993, invited seminar for the Division of Materical Science Group at Argonne National Laboratory.

     Ohio Section/ American Physical Society

Geographic sections of the American Physical Society perform an invaluable service to the society.  Their ability, through local meetings twice a year,  to reach members who might not be able to attend national meetings or conferences can be pivotal in providing a sense of belonging.  The local meetings of geographic sections give physics professionals in a specific region of the country the chance to hear and provide recent results in physics, to meet like-minded scientists, and to socialize.  If you are working in physics or a physics-related area and live in Ohio, Michigan, eastern Indiana, or northern Kentucky, please support the Ohio Section.  If you are already a member of the American Physical Society, there is NO EXTRA FEE for joining the Ohio Section. In fact, you can join at the OSAPS website linked above.

 
This page was last edited by B. Trees on 3/9/2008.