1 / 22

Transport properties: conductance and thermopower

Transport properties: conductance and thermopower. Rok Žitko Institute Jožef Stefan Ljubljana, Slovenia. Transport in nanostructures. Landauer formalism. Density of states per unit length:. (Includes factor 2 for spin). For T(E)=1 (ballistic conductor):. In general, at T=0:.

urbana
Download Presentation

Transport properties: conductance and thermopower

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Transport properties: conductance and thermopower Rok Žitko Institute Jožef Stefan Ljubljana, Slovenia

  2. Transport in nanostructures

  3. Landauerformalism

  4. Density of states per unit length: (Includes factor 2 for spin)

  5. For T(E)=1 (ballistic conductor): In general, at T=0: Multi-channel leads: resistance quantized contact resistance

  6. Scattering theory quasiparticle phase shifts Spin symmetry, single effective channel:

  7. Keldysh approach Relection symmetric problems: One impurity: Also known as the Meir-Wingreen formula

  8. Conductance of quantum dot (SIAM)

  9. Finite temperatures

  10. Effect of the magnetic field

  11. ħw Inelastic scattering ħw ħw Information aboutinternal degrees of freedom!

  12. Linear response theory for calculating the conductance of nanostructures Kubo (1957)

  13. Standard approach: Difficulty: the slope is difficult to calculate reliably! Solution: we can work with the global operator Nn itself!

  14. Test case: single-impurity Anderson model

  15. Proposed application:conductance of a S-QD-N structure • Open problem: the transition from G=4e2/h to G=2e2/h conductance as the gap closes Anyone interested?

  16. Transport integrals, thermopower

  17. B=0 d=0 (particle-hole symmetric point) spin Seebeck coefficient (charge) Seebeck coefficient

  18. Žitko, Mravlje, Ramšak, Rejec, manuscript in preparation. Spin thermopower is a sensitive probe of the response of the system in magnetic field.

More Related