arXiv:1811.07203 · Physical review. B./Physical review. B
Tunneling density of states, correlation energy, and spin polarization in the fractional quantum Hall regime
Gaurav Chaudhary, Dmitry K. Efimkin, Allan H. MacDonald
Abstract
We derive exact sum rules that relate the tunneling density-of-states of spinful electrons in the fractional quantum Hall regime to the spin-dependent many-body ground-state correlation energy. Because the tunneling process is spin-conserving, the two-dimensional (2D) to 2D tunneling current $I$ at a given bias voltage $V$ in a spin-polarized system is a sum of majority and minority spin contributions. The sum rules can be used to define spin-dependent gaps that we associate with peaks in 2D to 2D tunneling $I\text{\ensuremath{-}}V$ curves. We comment in the light of our sum rules on what recent tunneling experiments say about the spin-dependence of correlation energy contributions and propose new measurements that could provide more specific experimental estimates.