11 research outputs found
Level Two String Functions and Rogers Ramanujan Type Identities
The level two string functions are calculated exactly for all simply laced
Lie algebras, using a ladder coset construction. These are the characters of
cosets of the type , where is the algebra at level two and is
its rank. This coset is a theory of generalized parafermions. A conjectured
Rogers Ramanujan type identity is described for these characters. Using the
exact string functions, we verify the Rogers Ramanujan type expressions, that
are the main focus of this work.Comment: 26 page
Determination of the resistivity anisotropy of SrRuO by measuring the planar Hall effect
We have measured the planar Hall effect in epitaxial thin films of the
itinerant ferromagnet SrRuO3 patterned with their current paths at different
angles relative to the crystallographic axes. Based on the results, we have
determined that SrRuO3 exhibits small resistivity anisotropy in the entire
temperature range of our measurements (between 2 to 300 K); namely, both above
and below its Curie temperature (~150 K). It means that in addition to
anisotropy related to magnetism, the resistivity anisotropy of SrRuO3 has an
intrinsic, nonmagnetic source. We have found that the two sources of anisotropy
have competing effects
Paramagnetic anisotropic magnetoresistance in thin films of SrRuO3
SrRuO3 is an itinerant ferromagnet and in its thin film form when grown on
miscut SrTiO3 it has Tc of ~ 150 K and strong uniaxial anisotropy. We measured
both the Hall effect and the magnetoresistance (MR) of the films as a function
of the angle between the applied field and the normal to the films at
temperatures above Tc. We extracted the extraordinary Hall effect that is
proportional to the perpendicular component of the magnetization and thus the
MR for each angle of the applied field could be correlated with the magnitude
and orientation of the induced magnetization. We successfully fit the MR data
with a second order magnetization expansion, which indicates large anisotropic
MR in the paramagnetic state. The extremum values of resistivity are not
obtained for currents parallel or perpendicular to the magnetization, probably
due to the crystal symmetry.Comment: 3 pages, 3 figure