Prof. Dagan Yoram

  
Affiliation:School of Physics and Astronomy
Tel:  (972)-3-6405554
 
Fax: (972)-3-6422979
 
Email: yodagan@tau.ac.il
 
Personal Website:

 
Postal Address:School of Physics and Astronomy
Tel Aviv University
Tel Aviv 69978

Research Interest

1. Superconductivity in the nanoscale
Superconductivity is a macroscopic quantum phenomenon. However, when the superconducting specimen is constituted of weakly connected nano-grains many interesting physical phenomena occur. In our laboratory we are able to probe superconducting fluctuations and their dependence on the nanostructure of the sample.

2. Superconductivity and Magnetism in Oxide interfaces
It has been found that when two insulating nonmagnetic perovskites form an epitaxial interface this interface can become highly conductive, magnetic and even superconducting. Using our laser deposition facility we are producing and studying such interfaces to find out the microscopic and macroscopic origin of conductivity, superconductivity and magnetic effects.

3. Local and macroscopic orders in electron-doped cuprates
Electron-doped cuprates offer a unique laboratory for studying a variety of phenomena such as: superconductivity, quantum criticality and density waves. While the undoped material is antiferromagnetic upon adding charge carriers the material becomes superconducting. It is not clear whether these orders coexist and on what scale. We perform local and macroscopic tunneling study to clarify these issues that are eminent for understanding superconductivity in the cuprates.

 

TEM image of 8 unit cell crystal of LaAlO3 grown on top of SrTiO3 crystal although these materials are nonmagnetic insulators the interface between them is superconducting and has anomalous magnetic properties. Insert: RHEED oscillations indicative of deposition of exactly 8 unit cells.

 

The gap amplitude as a function of charge carrier concentration in electron-doped cuprate superconductors obtained by tunneling spectroscopy. This behavior is in strong contrast with the celebrated doping dependence of the pseudogap in hole-doped cuprates.

Selected Publications


  • M. Ben Shalom, C. W. Tai, Y. Lereah, E. Levy, A. Palevski, and Y. Dagan, Anisotropic magneto-transport effects at SrTiO3/LaAlO3 interfaces. arXiv:0902.2668 (2009 Submitted)
  • I. Diamant, R. L. Greene and Y. Dagan, single superconducting energy scale in electron-doped cuprates. (2009 Submitted) arXiv:
  • Y. Dagan and R. L. Greene, “Hole superconductivity in electron-doped cuprates”, Phys. Rev. B, 76, 024506 (2007).
  • Y. Dagan, R. Beck and R. L. Greene, “Dirty Superconductivity in the Electron-doped cuprate Pr2-xCexCuO4: Tunneling study”, Phys. Rev. Lett. 99, 147004 (2007).
  • Y. Dagan, M. C. Barr, W. M. Fisher, T. Dhakal, A. Biswas, R. Beck, and R. L. Greene, “Origin of the anomalous low temperature upturn in resistivity in the electron-doped cuprates.” Phys. Rev. Lett., 94, 057005 (2005).