Letter to the editor
Gogolin A.O., Ioselevich A.S.
Dear Editor: In some papers1'2 recently published in this journal, we proposed and analyzed a "quantum polaron": a distinctive formation which arises in the case of a strong quadratic interaction of an electron with soft phonon modes. We studied small-radius (antiadiabatic) quantum polarons and large-radius (adiabatic) quantum polarons in a space of arbitrary dimensionality D.