Thermopower as a tool to investigate many-body effects in quantum systems

Abstract

Measuring the thermopower of a confined quantum system reveals important information about its excitation spectrum. Our simulations show how this kind of transport spectroscopy is able to extract a clear signal for the onset of Wigner localization in a nanowire segment. This demonstrates that thermopower measurements provide a tool for investigating complex many-body quantum effects, which is less intrusive than the usual charge-stability diagram as no high source-drain bias is required. While the effect is most pronounced for weak tunnel coupling and low temperatures, the excited states also significantly affect the thermopower spectrum at moderate temperature, adding distinct features to the characteristic thermopower lineshape.

Spin-Thermoelectric Effects in a Quantum Dot Hybrid System With Magnetic Insulator

“…Recently, it turned out that the effects resulting from reduction of dimensionality can lead to increase of thermoelectric efficiency giving possibilities to create efficient heat-to-electric power converters [1][2][3][4] . Specifically, quantum dots seem to be good candidates for high-efficiency energy-converters as they reveal level and charge quantization which strongly affects the thermoelectric properties which has been shown theoretically [5][6][7][8][9][10][11][12][13][14][15][16] and observed in experiments [17][18][19][20][21] . Moreover, quantum interference effects in double quantum dots can additionally lead to large enhancement of thermoelectric response 22 .…”

Spin-thermoelectric effects in a quantum dot hybrid system with magnetic insulator

“…Recently, it turned out that the effects resulting from reduction of dimensionality can lead to increase of thermoelectric efficiency giving possibilities to create efficient heat-to-electric power converters 1-4 . Specifically, quantum dots seem to be good candidates for high-efficiency energy-converters as they reveal level and charge quantization which strongly affects the thermoelectric properties which has been shown theoretically [5][6][7][8][9][10][11][12][13][14][15][16] and observed in experiments [17][18][19][20][21] . Moreover, quantum interference effects in double quantum dots can additionally lead to large enhancement of thermoelectric response 22 .…”

Thermopower signatures and spectroscopy of the canyon of conductance suppression

“…[3][4][5][6][7][8][9][10][11] Here the intrinsic advantage of thermoelectric measurements is that they probe asymmetries around the Fermi level and therefore can easily provide information about excited states. 12 Close to a degeneracy of energy levels in a quantum dot, interference and correlation effects can play an important role for transport and lead to pronounced quantum mechanical phenomena. For a spin-degenerate quantum dot (QD) the conductance experiences an enhancement for low temperatures due to the Kondo effect.…”

“…In addition, it has been recently demonstrated that thermopower measurements can serve as an interesting tool to characterize complex scenarios due to coherences and interactions in nanoscale systems [3][4][5][6][7][8][9][10][11]. Here the intrinsic advantage of thermoelectric measurements is that they probe asymmetries around the Fermi level and therefore can easily provide information about excited states [12].…”