Spatially Resolving Electron Spin Resonance of π-Radical in Single-molecule Magnet

Abstract

The spintronic properties of magnetic molecules have attracted significant scientific attention. Special emphasis has been placed on the qubit for quantum information processing. The single-molecule magnet bis(phthalocyaninato (Pc)) Tb(III) (TbPc2) is one of the best examined cases in which the delocalized π-radical electron spin of the Pc ligand plays the key role in reading and intermediating the localized Tb spin qubits. We utilized the electron spin resonance (ESR) technique implemented on a scanning tunneling microscope (STM) and use it to measure local the ESR of a single TbPc2 molecule decoupled from the Cu(100) substrate by a two-monolayer NaCl film to identify the π-radical spin. We detected the ESR signal at the ligand positions under the resonance condition expected for an S = 1/2 spin. The results reveal that the π-radical electron is delocalized within the ligands and exhibits intramolecular coupling susceptible to the chemical environment.

On the magnetic bistability of small iron clusters used in scanning tunneling microscopy tip preparation

“…Notably, these clusters exhibit the highest barrier value aligning with the previously observed trend in lanthanides and single ions magnets [35,36]. With the recent increase in ESR-STM studies adopting the same strategy to make a tip [16,17,34,[37][38][39][40][41][42][43][44], we anticipate that our work helps to rationalize why this approach is successful.…”

An atomic-scale multi-qubit platform

“…Finally, the computational Hilbert space can be further expanded by using molecular qubits to construct three-dimensional architectures ( 38 ) or by using qudit systems with multiple electron and nuclear spin states ( 39 , 40 ). Such extensions rely on the specific benefit of our surface-based approach, in which a myriad of available spin species ( 17 , 41 – 43 ) and geometries ( 44 , 45 ) can be precisely assembled using scanning probe techniques.…”

Influence of the Magnetic Tip on Heterodimers in Electron Spin Resonance Combined with Scanning Tunneling Microscopy

“…Well-known approaches, such as optical manipulation of nitrogen-vacancy defects in diamond , and trapped ions, , magnetic control over quantum dots in semi- and superconducting circuits, , and electrical control over a single-molecule magnet in break junctions, , have been extensively explored to develop innovative quantum information technology. Recently, single spins adsorbed on surfaces have been employed for quantum-coherent control using STM combined with electron spin resonance (ESR-STM), − which provides the opportunity to position individual spins and build nanostructures with atomic-scale precision.…”