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Molec­u­lar Spin Systems on Surfaces

Paul Greule – Hector RCD Awardee Philip Willke

Single magnetic molecules can be used as build­ing blocks to construct new artifi­cial spin systems which are inter­est­ing for future quantum devices. We use scanning tunnel­ing microscopy (STM) combined with electron spin resonance (ESR) to construct and inves­ti­gate such spin systems on a surface. This enables the study of funda­men­tal spin proper­ties on the atomic scale and explor­ing novel magnetic phenom­ena in multi-spin systems.

For future quantum technolo­gies, molec­u­lar spins have emerged as possi­ble build­ing blocks. They can self-assem­ble on a surface which facil­i­tates the creation of quantum struc­tures with inter­act­ing spins. Addition­ally, the molecule struc­ture can be chemi­cally engineered which enables the design of their magnetic properties.

The aim of our research is to construct and inves­ti­gate a variety of multi-spin systems on a surface. The molecules are evapo­rated onto a conduct­ing or insulat­ing substrate and then inves­ti­gated via scanning tunnelling microscopy (STM). Besides the self-assem­bly of the molecules, the micro­scope is used to further build artifi­cial spin systems and to probe the physi­cal proper­ties of the molecules with a spatial resolu­tion on the sub-atomic scale. In our research, we focus on inves­ti­gat­ing the energy levels and spin states of the constructed systems. There­fore, the STM is combined with electron spin resonance (ESR) to get high energy resolu­tion and to coher­ently manip­u­late the spin states.

Thus, we are able to perform spin physics on the atomic scale while having the ability to engineer the magnetic proper­ties of our system. This will allow us to access emerg­ing magnetic phenom­ena of multi-spin systems for future quantum devices.

Molekulare Spin-Systeme auf Oberflächen_Paul Greule

Figure 1: Graph­i­cal repre­sen­ta­tion of the measure­ment. The inter­act­ing molecules on the surface are examined via the tunnel tip (green) of the scanning tunnel­ing microscope.

Paul Greule

Karlsruhe Insti­tute of Technology

Betreut durch


Philip Willke

Physics, Chemistry

Hector RCD Awardee since 2022