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Thermal control and generation of charge currents in coupled quantum dots
Author(s) -
Thierschmann Holger,
Arnold Fabian,
Mittermüller Marcel,
Maier Luis,
Heyn Christian,
Hansen Wolfang,
Buhmann Hartmut,
Molenkamp Laurens W.
Publication year - 2016
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201532608
Subject(s) - quantum dot , quantum tunnelling , thermoelectric effect , coupling (piping) , capacitive coupling , electron , condensed matter physics , charge (physics) , thermal , physics , materials science , optoelectronics , voltage , quantum mechanics , thermodynamics , metallurgy
This article reviews recent thermoelectric experiments on quantum dot (QD) systems. The experiments focus on two types of inter‐dot coupling: tunnel coupling and Coulomb coupling. Tunnel‐coupled QDs allow particles to be exchanged between the attached reservoirs via the QD system. Hence, an applied temperature bias results in a thermovoltage. When being investigated as a function of QD energies, this leads to the thermopower stability diagram. Here, largest thermovoltage is observed in the regions of the triple points. In a QD system which exhibits only capacitive inter‐dot coupling, electron transfer is suppressed. Such a device is studied in a three‐terminal geometry: while one QD connects to the heat reservoir, the other one can exchange electrons with two reservoirs at a lower temperature. When the symmetry of the tunneling coefficients in the cold system is broken, the device becomes an energy harvester: thermal energy is extracted from the heat reservoir and is converted into a directed charge current between the two cold reservoirs. This review illustrates the large potential of multi‐QD devices for thermoelectrics and thermal management at the nanometer‐scale.