Hall response of strongly correlated electrons

Theoretical understanding and the calculation of the Hall response of stron gly correlated electrons is addressed. It is shown that the Hall constant R -H in a tight-binding model of correlated electrons on a ladder at T = 0 ca n be expressed in terms of derivatives of the ground state energy with resp ect to external magnetic and electric fields. This novel method is used for the analysis of the t-J model on finite size ladders. It is found that for a single hole R-H is hole-like and close to the semiclassical value. In od d-leg ladders, R-H behaves quite regularly changing sign as a function of d oping, the variation being quantitatively close to experimental results in cuprates. The study is extended to general reactive Hall response and conse quently to quasi-1D systems where R-H can be simply related to 1-D charge s tiffness of the system.