  A nonadiabatic and robust method of excitation transfer in a non-Hermitian
tight-binding linear chain, assisted by an imaginary gauge field, is
theoretically proposed. The gauge field undergoes a linear gradient in time,
from a negative to a positive value, which results in an effective transfer of
excitation between the two edge sites of the chain. An imaginary (gain and
loss) gradient of site energy potentials is introduced to exactly cancel
nonadiabatic effects, thus providing an effective shortcut to adiabaticity and
pseudo-Hermitian dynamics. Numerical simulations indicate that the
non-Hermitian excitation transfer method is very robust against disorder in
hopping rates and site energy of the chain.
