Magnetic field tuning of the low temperature state in YbNiSi$_3$: magnetic field induced quantum criticality*

We present detailed, low temperature, magnetoresistance and specific heat data from measurements on YbNiSi$_3$ in magnetic field applied along the easy magnetic axis, $H \| b$. Initially the antiferromagnetic ground state changes into a field-induced metamagnetic phase at $\sim 16$ kOe ($T \to 0$). On further increase of magnetic field, magnetic order is suppressed to below 0.4 K at $\sim 85$ kOe. The functional behavior of the resistivity and specific heat is discussed in comparison with that of the few other stoichiometric, heavy fermion compounds with established field-induced quantum criticality.