  We present a general scheme to obtain work distribution in closed systems
under continuous quantum histories of corresponding "power" operator. The
scheme is tested by analytically calculating the quantum work distribution for
a prototype model of a center-shifted one-dimensional quantum harmonic
oscillator. Furthermore, its relationship to the path integral formalism with
the Wick rotation is immediately noticed. We find that, based on the continuous
measurement, generally Jarzynski equality in quantum regime is not valid,
though it is recovered in high-temperature limit. Also we briefly explore the
extension to open systems, in which the work done and heat transfer can be
calculated in the same set of quantum histories. Our results for this model can
be directly verified by single-molecule force spectroscopy.
