Collapse and enhancement of the heavy fermion state in CeCu₆ under magnetic field and pressure

We measured the electrical resistivity under magnetic field and pressure and de Haas van Alphen (dHvA) oscillations in CeCu₆. The A value in the Fermi liquid relation of the electrical resistivity ρ = ρ0 + AT ² and the cyclotron effective mass are reduced with increasing magnetic fields and pressures. The A value, however, becomes distinct and/or is enhanced at the metamagnetic field, especially, in a characteristic pressure region where the electronic state deviates from the heavy fermion state, for example, at 2.00 GPa.