Atomic-scale spin sensing with a single molecule at the apex of a scanning tunneling microscope

Abstract

Recent advances in scanning probe techniques rely on the chemical functionalization of the probe-tip termination by a single molecule. The success of this approach opens the tantalizing prospect of introducing spin sensitivity through the functionalization by a magnetic molecule. Here, we use a nickelocene-terminated tip (Nc-tip), which offers the possibility of producing spin excitations on the tip apex of a scanning tunneling microscope (STM). We show that when the Nc-tip is a hundred pm away from point contact with a surface-supported object, magnetic effects may be probed through changes in the spin excitation spectrum of nickelocene. We use this detection scheme to simultaneously determine the exchange field and the spin polarization of the sample with atomic-scale resolution. Our findings demonstrate that the Nc-tip is a powerful probe for investigating surface magnetism with STM, from single magnetic atoms to surfaces.

Spin dependent transmission of nickelocene-Cu contacts probed with shot noise

“…The simulated constant-current STM images using such a tip are in good agreement with the experimental ones 34 . Similar results have been reported for Nc-functionalized tips on Ag(110) 37 and Cu(111) 38 . The tilt disappears as the tip is brought closer to the surface.…”

Large-extended 2D supramolecular network of dipoles with parallel arrangement on a Si(111)–B surface

“…We report the formation of ordered and extended 2D supramolecular network of 1-(4"-cyanobiphenyl)-4-(4"-methoxybiphenyl)-2,5-bis(propyloxy)benzene (LDipCC) molecule on a Si(111)-B surface. Scanning Tunnelling Microscopy (STM), Density Functional Theory (DFT) calculations, which is a powerful tool to elucidate molecular adsorption on surfaces, 25,26,27 and STM simulations were used to demonstrate that the LDipCC molecule is self-assembled into a highly homogeneous parallel arrangement on the Si(111)-B surface. In addition, Si(111)-B is a weakly reactive surface, anti-parallel arrangement has been mostly observed on Cu(111), but not on less reactive surfaces such as Au(111) and HOPG.…”

Quantum state manipulation of single atom magnets using the hyperfine interaction

“…As classical magnetic bits, SAMs and SMMs have demonstrated magnetic bistability [1,3,4,8], even above liquid nitrogen temperatures [5], readability and writability [1,[9][10][11][12], and self-assembly into periodic arrays [4,8]. For quantum information processing, the precise control over their local environment, intrinsic isolation, and relative ease of on-surface deposition render SAMs and SMMs attractive qubit candidates [13][14][15][16][17][18][19][20]. Early experiments have shown promise, so far culminating with an experimental realization of Grover's search algorithm on a single molecule [7].…”