Scientific Activities
Seminars
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Seminar of Center for Theoretical Physics: | |
| Title | Magneto-thermopower of a quantum dot: effects of asymmetry in Kondo channels |
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| Speaker | Dr. Nguyen Thi Kim Thanh |
| Affiliation | Physics Department, University of Cincinnati & Center for Theoretical Physics, Institute of Physics |
| Date | Tuesday, 07-02-2012 |
| Time | 10:00 AM |
| Location | Meeting room on the 1st floor, Institute of Physics, 10 Dao Tan, Ba Dinh, Hanoi |
| Abstract | In my presentation, I will talk about the effects of magnetic field on the thermoelectric coefficients (TCs) of a single-electron transistor based on a quantum dot strongly coupled to one lead by a single-mode quantum point contact (QPC) and weakly coupled to the second lead by a tunnel barrier. The magnetic field induces an asymmetry in transmission of spin-up and spin-down channels at the QPC. The result shows the appearance of two new energy scales: on the magnetic field (the field corresponding to a full polarization of the QPC) and: depending on a reflection amplitude and charging energy . The behavior of TCs is discussed in three regimes. The "giant Fermi liquid" regime in which the TCs behave as those in the Fermi liquid theory do at temperatures . Proximity to "strong non Fermi liquid" regime characterized by of thermopower can be seen at . The perturbative "weak non Fermi liquid" regime with holds at . The similarities of the model with multi-channel Kondo systems and possible experimental tests for verification of the non-Fermi-liquid transport through the quantum dot system are discussed. |