| Date | 8th, Dec 2021 |
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As each electron passes through the nanometer gap, it has to choose which of the molecular states it will occupy during the time it spends on the molecule, the number of states and their relative probabilities of occupation – all parameters of entropy. By measuring this entropy directly and its dependence on the magnetic field, the group of researchers gained information about the energy levels and the spin states in the molecule. Unlike existing methods, this new method can be readily applied to any kind of nano-scale system.
Chunwei Hsu, who performed the experiment, explains: ‘’Entropy is a thermodynamic quantity, describing the disorder in a classical system. In a quantum system, it essentially quantifies the occupancy of states and thus is important for understanding chemical processes and exotic physical systems, such as Kondo states and Majorana fermions. While researchers can rarely address entropy in these nanoscale systems, we managed to make a tool to measure entropy via the thermocurrent.” Thermocurrent spectroscopy may be useful in both chemical synthesis and single-molecule electronics, for example in the design new of OLED applications used in the creation of digital displays, and more efficient thermoelectric power generators.
