  We introduce and review briefly the phenomenon of quantum annealing and
analog computation. The role of quantum fluctuation (tunneling) in random
systems with rugged (free) energy landscapes having macroscopic barriers are
discussed to demonstrate the quantum advantage in the search for the ground
state(s) through annealing. Quantum annealing as a physical (analog) process to
search for the optimal solutions of computationally hard problems are also
discussed.
