Fig. 2: Manipulation process of single polarons.
From: Atomic-scale manipulation of single-polaron in a two-dimensional semiconductor

a Typical I–V curve sweeping between −1.2 V to +1.1 V measured on a defect-free region of monolayer CoCl2 surface, showing two current jumps. b–d The process of a single operation event by applying bias pulses. b a voltage pulse of 800 mV applying at a clean spot on the surface. c A voltage pulse of −1.0 V applying at center of one ring. d A voltage pulse of −1.2 V applying at center of the ring. The left panel (1) are the dI/dV maps of an area before event, and the right panel (3) are the dI/dV maps of same area after event. The middle panel (2) are the recorded current change during voltage pulsing. The stars mark the tip positions during the pulses. Scale bars, 2 nm for (b), and 3 nm for (c, d). e, f Two series of dI/dV maps, from top panels to bottom panels, showing successive manipulation events. The (solid/hollow) green, yellow and blue arrows represent writing, transition and erasure events (before/after), respectively. Scale bars, 9 nm. g A dI/dV map showing an ‘IOP’ pattern which has been artificially created by successive writing processes. “Hi” and “Lo” in the color scale are the abbreviation of “High” and “Low”, corresponding to higher and lower relative intensity of signal. Scale bar, 12 nm. The scanning parameters of all dI/dV maps are Vs = 750 mV, I = 5 pA, 90 nm × 23 nm, and with the same tip.