Orthofermion statistics and its application to the infinite U Hubbard model

We present an algebra of the creation and annihilation operators for spin fermions which avoid double occupancy of an orbital state. These fermions, called orthofermions, obey the quantum statistics in which the state vector is antisymmetric only for the exchange of the orbital indices. Because of this peculiar property, representation of the number and the spin operators in terms of creation and annihilation operators is much more complex compared to the usual representation of spin fermions. We have found that this representation is very similar to the representation of the number operator in the infinite statistics of Greenberg. As an application of this statistics, we study the thermodynamics of the infinite U Hubbard model and obtain the known exact results in one dimension. Since our approach is valid in any dimension, it can be employed to ascertain the accuracy of the approximate solutions of the Hubbard model.