Effect of a magnetic field on Mott-Hubbard systems

The effect of a magnetic field on Mott-Hubbard systems is investigated by studying the half-filled Hubbard model in the limit of infinite dimensions. A first-order metamagnetic transition between the strongly correlated metal and the Mott insulator is found for a critical value of the applied field. The field and temperature dependence of the magnetization, one-particle properties and susceptibility are studied and compared to the Gutzwiller approximation. The experimental relevance for transition-metal oxides and liquid $^{3}He$ is discussed.