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Labelling and preparation of magnetic units in pure quantum states

Controlled deposition of magnetic qubits in pure quantum spin states:

- Approach 1: In our group we have developed a new soft, reliable and simple methodology to address individual Mn12 molecules onto a film surface. Such a methodology is based on the preparation of nanocomposite thin films, made from a polycarbonate polymeric matrix and an Mn12 complex, and the subsequent treatment with different organic solvent vapours. Solvent treatment originates that a small fraction of the Mn12 molecules emerge to the surface of the film with an aggregation state that can be controlled at will, depending on the nature of the solvent. Moreover, we have shown that the location Such a methodology is based on the preparation of a polymeric thin-film made from a polycarbonate matrix and Mn12 molecules, which is moulded with a master and exposed to vapours of an organic solvent. Such a solvent treatment smooth out the surfaces relieves of the polymeric replica and the Mn12 molecules that were dispersed in the protruding regions of the replica concentrate in the original protruding features but do not diffuse laterally thus originating a compositional contrast of Mn12 on the polymeric surface. Magnetic response of the patterned aggregates of Mn12 molecules, using Magnetic Force Microscopy (MFM), follows accurately the compositional spatial modulation of the pattern, so it is possible to encode and read out information with such molecular patterns working at the paramagnetic regime from mesoscopic down to nanometre length scales. This is the first time that small aggregates and individual SMM's are deposited and can be individually screened either by AFM and MFM microscopies. The advantages of this approach are considerable. First, the polymeric matrix plays a critical role in stabilising the SMM as well as enhancing the overall mechanical strength of the film. Second, polycarbonates are a commercially important and technologically interesting polymers that have a combination of properties not found in any other plastic, including very high impact strength, creep resistance, optical clarity, and a low moisture absorption. And finally, the resulting nanocomposite thin films are fully compatible with nowadays magnetic and magneto-optical storage technologies, where polycarbonate resins are used as the basic support for the fabrication of disks.

- Approach 2: Along the second year, in collaboration with an Italian team, we have demonstrated that arrays of nanometre-sized aggregates, each made of a few hundred single-molecule magnets derived from Mn12 complexes, can be patterned on large areas by self-organisation assisted by stamps on a surface in a de-wetting regime. The large length scale is imposed by the motif of the stamp protrusions, and the smaller length scales, viz., the size and distance of the molecular aggregates, are controlled by deposition and growth phenomena occurring in a volume confined beneath the protrusions by capillary forces. The method is general to a variety of molecular materials and substrates because repulsive, as opposed to specific, interactions are required. Our result hints at the possibility of sustainable patterning of single-molecule magnets for ultra-high-density magnetic storage and quantum computing.

Informations connexes

Reported by

Centro Nacional de Microelectronica (IMB-CSIC)
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