Magnetoresistance and spintronic anisotropy induced by spin excitations along molecular spin chains

Abstract

Electrically manipulating the quantum properties of nano-objects, such as atoms or molecules, is typically done using scanning tunnelling microscopes and lateral junctions. The resulting nanotransport path is well established in these model devices. Societal applications require transposing this knowledge to nano-objects embedded within vertical solid-state junctions, which can advantageously harness spintronics to address these quantum properties thanks to ferromagnetic electrodes and high-quality interfaces. The challenge here is to ascertain the device's effective, buried nanotransport path, and to electrically involve these nano-objects in this path by shrinking the device area from the macro- to the nano-scale while maintaining high structural/chemical quality across the heterostructure. We've developed a low-tech, resist- and solvent-free technological process that can craft nanopillar devices from entire in-situ grown heterostructures, and use it to study magnetotransport between two Fe and Co ferromagnetic electrodes across a functional magnetic CoPc molecular layer. We observe how spin-flip transport across CoPc molecular spin chains promotes a specific magnetoresistance effect, and alters the nanojunction's magnetism through spintronic anisotropy. In the process, we identify three magnetic units along the effective nanotransport path thanks to a macrospin model of magnetotransport. Our work elegantly connects the until now loosely associated concepts of spin-flip spectroscopy, magnetic exchange bias and magnetotransport due to molecular spin chains, within a solid-state device. We notably measure a 5.9meV energy threshold for magnetic decoupling between the Fe layer's buried atoms and those in contact with the CoPc layer forming the so-called 'spinterface'. This provides a first insight into the experimental energetics of this promising low-power information encoding unit.

References in corpus (14)

• Antiferromagnetic spintronics
• Unravelling the role of the interface for spin injection into organic semiconductors
• Molecular Spin Qudits for Quantum Algorithms
• Magnetoresistance through a single molecule
• Electrical switching in a magnetically intercalated transition metal dichalcogenide
• Atomic-scale spin sensing with a single-molecule at the apex of a scanning tunneling microscope
• Spintronic magnetic anisotropy
• Tunable magnetoresistance in an asymmetrically coupled single molecule junction
• Magnetic Anisotropy Variations and Non-Equilibrium Tunneling in a Cobalt Nanoparticle
• Ground-state spin blockade in a single-molecule junction
• Disentangling magnetic hardening and molecular spin chain contributions to exchange bias in ferromagnet/molecule bilayers
• A nano-carbon route to rare earth free permanent magnetism
• Correlation Driven Transport Asymmetries Through Coupled Spins
• Spin-driven electrical power generation at room temperature

Cited by in corpus (4)

• Quantum advantage in a molecular spintronic engine that harvests thermal fluctuation energy
• Low-energy, ultrafast spin reorientation at competing hybrid interfaces with tunable operating temperature
• Encoding information onto the charge and spin state of a paramagnetic atom using MgO tunnelling spintronics
• Imaginary Time Spectral Transforms for Excited State Preparation