Lab Home | Phone | Search
	Center for Nonlinear Studies
	Home  ▶ People   Current   Executive Committee   Postdocs   Visitors   Students   Research   Publications  ▶ Conferences   Workshops   Sponsorship  ▶ Talks   Seminars   Postdoc Seminars Archive   Quantum Lunch   Quantum Lunch Archive   P/T Colloquia   Archive   Ulam Scholar     Postdoc Nominations  ▶ Student Requests   Student Program  ▶ Visitor Requests   Description   Past Visitors  ▶ Services   General     History of CNLS     Maps, Directions   CNLS Office   T-Division   LANL				Thursday, July 07, 20053:30 PM - 4:00 PMCNLS Conference Room (TA-3, Bldg 1690) Seminar Colloid system dynamics in the presence of a flashing potential Andras LibalUniversity of Notre Dame Colloid system dynamics have been extensively studied in the presence of random and periodic 1D and 2D substrates. With dynamic holographic optical tweezers it is possible to create a flashing periodic potential for the colloid system, and study the response of this system to different driving forces. We are conducting MD simulations of these systems and our results show that there are Shapiro steps (phase locking) in the case of a uniform drive, and that it is possible to construct a ratchet using an AC drive and the flashing potential. We found that this ratchet's effectiveness depends on the ratio of the pinning and AC driving force and on the commesuration between the pinning substrate and the colloid system.