  Probing the universal low temperature magnetic field scaling of
Kondo-correlated quantum dots via electrical conductance has proved to be
experimentally challenging. Here, we show how to probe this in nonlinear
thermocurrent spectroscopy applied to a molecular quantum dot in the Kondo
regime. Our results demonstrate that the bias-dependent thermocurrent is a
sensitive probe of universal Kondo physics, directly measures the splitting of
the Kondo resonance in a magnetic field, and opens up possibilities for
investigating nanosystems far from thermal and electrical equilibrium.

Mesoscale and Nanoscale Physics;Strongly Correlated Electrons