Multiparameter quantum critical metrology

Single parameter estimation is known to benefit from extreme sensitivity changes in quantum critical systems. However, the simultaneous of multiple parameters generally limited due incompatibility arising nature underlying system. A key question whether criticality may also play a positive role reducing parameters. We argue that this case and verify prediction paradigmatic many-body systems close first second order phase transitions. The antiferromagnetic ferromagnetic 1-D Ising chain with both transverse longitudinal fields are analysed across different regimes criticality.