Thermoelectric effect in an Aharonov-Bohm ring with an embedded quantum dot

Abstract

Thermoelectric effect is studied in an Aharonov-Bohm interferometer with an embedded quantum dot (QD) in the Coulomb blockade regime. The electrical conductance, electron thermal conductance, thermopower, and thermoelectric figure-of-merit are calculated by using the Keldysh Green's function method. It is found that the figure-of-merit ZT of the QD ring may be quite high due to the Fano effect originated from the quantum interference effect. Moreover, the thermoelectric efficiency is sensitive to the magnitude of the dot-lead and inter-lead coupling strengthes. The effect of intradot Coulomb repulsion on ZT is significant in the weak-coupling regime, and then large ZT values can be obtained at rather high temperature.

Intrinsic magnetism and spontaneous band gap opening in bilayer silicene and germanene

“…However, a sizable band gap (E g ), which is crucial for electronic and optical applications, does not yet exist in free-standing silicene or germanene, though none-zero band gaps were proposed with chemical functionalization. 24 In this work our first-principles calculations reveal that both intrinsic magnetism and band gap opening can be simultaneously achieved in the 2D bilayer silicene (germanene) system. This is because of the strong covalent interlayer bonds established, which break the original π-bonding network within each layer.…”

Thermoelectric transport properties of a T-shaped double quantum dot system in the Coulomb blockade regime

“…Consider now in more detail the slow detector limit of the system. One possibility to tune the system's thermoelectric properties is to vary the coupling between the conduction electrons in the leads and the localized electrons in the main dot (∆/t) [32]. As one can see from Figure 1, in the case of the T-shaped double quantum dot Other parameters for the system are ε1/t = −0.2, U1/t = 5, U2/t = 2, kBT /t = 0.1, and εF /t = 0.…”

Thermoelectric transport through a T-shaped DQD connected to ferromagnetic and superconducting electrodes

“…A lot of research work has shown that the quantum interference effect strongly affects the thermoelectric coefficient. [13][14][15][16][17][18][19][20][21][22][23] For instance, A-B oscillations of the thermoelectric effect in an A-B ring has shown to be strongly dependent on the magnetic flux. 13,14 The Fano effect [15][16][17][18][19] and the Dicke effect [20][21][22][23] can lead to strong violation of the Wiedemann-Franz law, and improve the figure of merit in the vicinity of the resonance.…”