  We present a theoretical proposal for the Herzberg circuit and controlled
accumulation of Berry's phase in a chirality-based coded qubit in a triangular
triple quantum dot molecule with one electron spin each. The qubit is encoded
in the two degenerate states of a three spin complex with total spin $S=1/2$.
Using a Hubbard and Heisenberg model the Herzberg circuit encircling the
degeneracy point is realized by adiabatically tuning the successive on-site
energies of quantum dots and tunnel couplings across a pair of neighbouring
dots. It is explicitly shown that encircling the degeneracy point leads to the
accumulation of the geometrical Berrys phase. We show that only triangular but
not linear quantum dot molecule allows for the generation of Berry's phase and
we discuss a protocol to detect this geometrical phase.
