Institute for Astronomy and Astrophysics

The magnetic field within a superconducting neutron star

February 2013

Sam Lander

Superfluidity and superconductivity only occur on the Earth in special materials at extremely low temperatures. By contrast, these exotic states of matter are expected to be commonplace in neutron stars: the neutrons form a superfluid and the protons a superconductor. In 'normal' matter - main-sequence stars, white dwarfs and most material on Earth - the magnetic force that acts on charged particles is the familiar Lorentz force. For superconducting matter the magnetic force is quite different - but most work on neutron stars still uses the Lorentz force anyway, for simplicity.

Here we lay some foundations for including proton superconductivity in neutron star models. We derive a single equation governing an equilibrium magnetic field in a superconductor and solve it numerically. Our solutions show qualitative differences from earlier models that assumed normal matter.

Phys. Rev. Letters, 110, 1101 (2013) arXiv e-print (arXiv:1211.3912)