We use the Becchi-Rouet-Stora-Tyutin (BRST) method to quantize the t-J
model in the U(1) gauge slave boson representation. While the temporal
component of the gauge field plays a role of a Lagrange multiplier to enforce
the no double occupancy constraint, the spatial components do that to enforce
the zero counterflow constraint of the spinon and holon currents. The BRST
quantization guarantees the gauge invariance of the theory and removes the
redundant gauge degrees of freedom by proper gauge fixing conditions while the
no double occupancy and zero counterflow constraints are exactly retained.
Furthermore, Fradkin-Vilkovisky gauge fixing conditions endow the gauge field
with dynamics. This turns the strongly correlated electron model into a weakly
coupled slave boson model, most of whose physical observables can be calculated
by the conventional quantum many-body perturbation theory. We focus on the
properties of the strange metal phase in the t-J model. The electron
momentum distribution and the spectral function are calculated, and their
non-Fermi liquid behavior agrees with the angle resolved photoemission
spectroscopy measurements for the cuprate materials. We also study the
responses of the strange metal state to the external electromagnetic fields.
The non-Fermi liquid anomalies observed in cuprates are captured by our
calculations. Especially, we find that the Hall resistivity decreases as
temperature raises and the sign of the Hall resistivity varies from negative to
positive when the dopant concentration varies from the optimal doping one to
underdoping one when the temperature T>Tβ.Comment: v1: 20 pages; v2: 21 pages, 8 figures. A few changes and new
references added. All comments are welcom