Quantum oscillations in surface-tip transfer of adatoms on AFM/STM with a dissipative environment

The influence of a dissipative environment on quantum coherence in surface-tip adatom transfer in AFM/STM is studied within an adiabatic approach. taking into account the slow motion of the tip with respect to an adsorption site. It is shown that coherent tunneling is the dominant mechanism of adatom transfer at temperatures below 10 K for insulators and semiconductors, and below 0.1 K for metals. The negative influence of electron and phonon polaron effects, which manifests itself in the destruction of coherence, may be noticeably compensated by potential fluctuations due to atom vibrations. As a result, the renormalized coherent tunneling amplitude may be even greater than the ground energy level splitting in the absence of a dissipative environment. Prospective pratical applications of the quantum coherence in adatom transfer are discussed. (C) 1997 Elsevier Science B.V.