Previously I wrote a post about a wide range of strongly correlated electron materials that exhibit a very puzzling and unexplained magnetoresistance. In particular, the dependence on the direction of the magnetic field is the opposite to what one expects for the Lorentz force.
I recently became aware of another example, the underdoped cuprate superconductor
Y1-xPrxBa2Cu3O7,
The angular dependence of the intra-layer magnetoresistance is described in this PRL and interlayer magnetoresistance data is available in a 2006 PRB.
The authors suggest that the anomalous angular dependence arises because the magnetoresistance is not dominated by quasi-particles but rather the flux flow from fluctuating superconducting vortices associated with pseudogap state.
There is an alternative explanation of the data due to Dora, Maki, and Virosztek. They consider an underlying d-density wave state [which has a pseudogap]. They claim that their theory describes some of the other materials in my original post and the heavy fermion material CeCoIn5. Hence, I need to understand this theory better. One question I have is how it deals with the violation of Kohler's rule. [I suspect it comes about due to thermal excitations across the pseudogap].
Subscribe to:
Post Comments (Atom)
From Leo Szilard to the Tasmanian wilderness
Richard Flanagan is an esteemed Australian writer. My son recently gave our family a copy of Flanagan's recent book, Question 7 . It is...
-
Is it something to do with breakdown of the Born-Oppenheimer approximation? In molecular spectroscopy you occasionally hear this term thro...
-
If you look on the arXiv and in Nature journals there is a continuing stream of people claiming to observe superconductivity in some new mat...
-
I welcome discussion on this point. I don't think it is as sensitive or as important a topic as the author order on papers. With rega...
No comments:
Post a Comment