Radio Frequency Scanning Tunneling Spectroscopy for Single-Molecule Spin Resonance

Abstract

We probe nuclear and electron spins in a single molecule even beyond the electromagnetic dipole selection rules, at readily accessible magnetic fields (few mT) and temperatures (5 K) by resonant radio-frequency current from a scanning tunneling microscope. We achieve subnanometer spatial resolution combined with single-spin sensitivity, representing a 10 orders of magnitude improvement compared to existing magnetic resonance techniques. We demonstrate the successful resonant spectroscopy of the complete manifold of nuclear and electronic magnetic transitions of up to ΔI(z)=±3 and ΔJ(z)=±12 of single quantum spins in a single molecule. Our method of resonant radio-frequency scanning tunneling spectroscopy offers, atom-by-atom, unprecedented analytical power and spin control with an impact on diverse fields of nanoscience and nanotechnology.

Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

“…Applying a similar approach to the spin measurement of individual paramagnetic point defects has been proposed [6,7], yet after more than two decades since the first single-spin detection experiments [8], the spatial resolution of various electrical [9][10][11] , optical [12] and even scanning probe based single spin detection techniques [13][14][15] is one to two orders of magnitude above the localization of the paramagnetic states [8,9,11,13,14]. This limitation makes the application of these spin measurement techniques for a selective readout of adjacent paramagnetic states difficultor, as recently demonstrated, they are based on either scanning tunneling microscopy (STM) [15], spinpolarized scanning tunneling microscopy [16,17] or magnetic exchange force microscopy [17,18,19], all of which employ conductive probe tips, with free carriers that could limit spin coherence times of qubits when the spin readout is used for quantum information applications.…”

Molecular Spins in the Context of Quantum Technologies

“…With respect to bare magnetic atoms, the presence of an organic ligand seems to delocalize the magnetic features of the molecule [41] and data interpretation is still under debate. Recently interesting experiments on the manipulation and read out of molecular spin (TbPc 2 ) by radio frequency [42] and single magnetic atom on a surface by pulsed microwave sequences have been reported [43].…”

Probing strongly hybridized nuclear-electronic states in a model quantum ferromagnet

“…A similar line of effort has achieved more recently single-molecule magnetic resonance with a rare-earth ion [11]. Furthermore, strong hybridization is of great interest in quantum information science [12][13][14].…”