Abstract
The Sarma state is a superconducting state which exists at a high magnetic
field and has an electronic structure more similar to a normal metal. Although
normally an unstable thermodynamic state, the Sarma state has
been predicted to occur in multiband superconductors with sufficient gap
anisotropy. In nonsymmorphic systems, strongly spin-orbit coupled electrons
and weakly spin-orbit coupled electrons can coexist. The strongly
spin-coupled electrons experience a weak Zeeman effect for a magnetic
field and weakly spin-coupled electrons experience a normal magnitude
of the Zeeman effect. The different strengths of the Zeeman effect on the
two Fermi surfaces allow the Sarma state to occur.
The aim of this project is to use mean-field theory to obtain the magnetic
field-temperature phase diagram for a superconductor with nonsymmorphic
structure and to determine the existence of the Sarma state. Furthermore,
we study the variation of thermodynamic quantities such as specific heat,
magnetization and susceptibility across the phase diagram to find evidence
for the Sarma state.