  Quantum correlations are of fundamental importance in quantum phenomena and
quantum information processing studies. The measure of quantum correlations is
one central issue. The recently proposed measure of quantum correlations, the
local quantum uncertainty (LQU), satisfies the full physical requirements of a
measure of quantum correlations. In this work, by using operator relaxation, a
closed form lower bound of the LQU for arbitrary-dimensional bipartite quantum
states is derived. We have compared the lower bound and the optimized LQU for
several typical quantum states.
