Ground-state spin blockade in a single-molecule junction

Joeri de Bruijckere; Pascal Gehring; Mario Palacios-Corella; Miguel Clemente-León; Eugenio Coronado; Jens Paaske; Per Hedegård; Herre S. J. van der Zant

doi:10.1103/physrevlett.122.197701

arXiv · 1812.06721

Ground-state spin blockade in a single-molecule junction

Joeri de Bruijckere·Pascal Gehring·Mario Palacios-Corella·Miguel Clemente-León·Eugenio Coronado·Jens Paaske·Per Hedegård·Herre S. J. van der Zant

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Abstract

It is known that the quantum-mechanical ground state of a nano-scale junction has a significant impact on its electrical transport properties. This becomes particularly important in transistors consisting of a single molecule. Due to strong electron-electron interactions and the possibility to access ground states with high spins, these systems are eligible hosts of a current-blockade phenomenon called ground-state spin blockade. This effect arises from the inability of a charge carrier to account for the spin difference required to enter the junction, as that process would violate the spin selection rules. Here, we present a direct experimental demonstration of ground-state spin blockade in a high-spin single-molecule transistor. The measured transport characteristics of this device exhibit a complete suppression of resonant transport due to a ground-state spin difference of 3/2 between subsequent charge states. Strikingly, the blockade can be reversibly lifted by driving the system through a magnetic ground-state transition in one charge state, using the tunability offered by both magnetic and electric fields.

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Joeri de Bruijckere, Pascal Gehring, Mario Palacios-Corella, Miguel Clemente-León, Eugenio Coronado, Jens Paaske, Per Hedegård, Herre S. J. van der Zant. 2018-12-17. Ground-state spin blockade in a single-molecule junction. https://doi.org/10.1103/physrevlett.122.197701

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