Lineshape of the thermopower of quantum dots

Svensson, Sofia Fahlvik; Persson, Ann; Hoffmann, E.; Nakpathomkun, Natthapon; Nilsson, Henrik; Xu, Hongqi; Samuelson, Lars; Linke, Heiner

doi:10.1088/1367-2630/14/3/033041

Cited by 77 publications

(96 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We now turn to the situation of arbitrary level width and position. In this case, the integrals in (15) and (16) have to be evaluated numerically. The main results of our analysis are summarized in figure 8 where we defined the average temperature T = (T C + T R )/2 and the temperature bias ∆T = T C − T R .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Thermoelectric energy harvesting with quantum dots

2014

View full text Add to dashboard Cite

Abstract. We review recent theoretical work on thermoelectric energy harvesting in multi-terminal quantum-dot setups. We first discuss several examples of nanoscale heat engines based on Coulomb-coupled conductors. In particular, we focus on quantum dots in the Coulomb-blockade regime, chaotic cavities and resonant tunneling through quantum dots and wells. We then turn towards quantum-dot heat engines that are driven by bosonic degrees of freedom such as phonons, magnons and microwave photons. These systems provide interesting connections to spin caloritronics and circuit quantum electrodynamics.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Further studies have been carried out on open quantum dots [12] and carbon nanotubes [13,14]. More recently, the thermopower of quantum dots defined in nanowires has been studied [15,16]. Interestingly, these experiments could observe nonlinear thermoelectric effects [16].…”

Section: Introductionmentioning

confidence: 99%

Thermoelectric energy harvesting with quantum dots

2014

View full text Add to dashboard Cite

show abstract

“…If higher-order processes are present, the sawteeth shrink and plateaus will appear between them. 28,30,31 This provides a limit for the observation of excited states for systems with a high conductance, as discussed in Ref. 19.…”

mentioning

confidence: 98%

“…Regarding the technical realization, thermal biasing of short segments of nanowires has been demonstrated, 27,28 which, however, was somewhat cumbersome and required careful tuning to avoid disturbances in the measurement circuit. A recent improvement in biasing technique 29 allows for highly local (avoiding overall heating), continuously tunable, and electrically non-intrusive thermal biasing, which strongly facilitates the proposed thermopower measurements.…”

mentioning

confidence: 99%

“…4). However, they add distinct features to the thermopower lineshape (which at finite temperature evolves away from a sawtooth pattern 8,28 ), and even shift the zeroes off their usual positions (at the Coulomb peak positions and in the middle between those, see the magenta dotted line). It is an important message from this work that such shifts and distortions, which are commonly seen in experiment, are not experimental artifacts but carry important information.…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

Kristinsdottir

Bengtsson

Linke

et al. 2014

Applied Physics Letters

View full text Add to dashboard Cite

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.

show abstract

Using Polymer Electrolyte Gates to Set‐and‐Freeze Threshold Voltage and Local Potential in Nanowire‐based Devices and Thermoelectrics

Svensson

Burke

Carrad

et al. 2014

Adv Funct Materials

View full text Add to dashboard Cite

polymer electrolyte gated nanowire transistor consists of a salt-laden polymer gel, e.g., LiClO 4 in poly(ethylene oxide), spanning a gap between a metal gate electrode and the nanowire. A voltage applied to the gate electrode drives migration of Li + and ClO − 4 ions to form electric double layers at the electrode/electrolyte and electrolyte/nanowire interfaces. [ 15 ] This effective transfer of gate charge to within ≈1 nm of the nanowire gives considerably improved gate coupling and sub-threshold characteristics. [ 13,14 ] Whereas earlier work focused on organic semiconductor transistors, [ 15,16 ] and semiconductor nanowire transistors with unpatterned polymer electrolyte fi lms, [ 13 ] this paper presents the fi rst study of the low temperature electrical properties of a nanowire transistor featuring a nanoscale polymer electrolyte patterned by electron beam lithography. [ 14 ] In this paper we focus our attention on the properties and potential uses of a unique aspect of polymer electrolyte gates, namely the fact that the ionic mobility drops rapidly to zero as the temperature T is reduced below approximately 220 K. [ 16 ] This enables the electrolyte's ion distribution to be set and "frozen in" to give a fi xed external charge environment near the nanowire's surface. It holds interesting potential uses in quantum transport studies, which are typically performed at T < 4 K; for example, the ability to freeze in the ion distribution in polymer electrolyte gated nanowires has been recently used to study spin-orbit effects in nanowires. [ 13 ] Here we show that this approach can be extended to add two new features: a) the ability to tune the threshold voltage for conventional electrostatic gates, for example, an insulated, doped substrate [ 6 ] over a wide range; and b) the ability to set the disorder potential for nanowire transistors and quantum devices. The disorder potential breaks the nanowire into a string of quantum dots coupled in series, [ 17 ] with properties that can be tuned using the voltage applied to the polymer electrolyte gate. We characterize our devices using conductance and thermovoltage measurements with a key result being the demonstration that local polymer electrolyte gates are fully compatible with thermoelectric measurements of nanowires [18][19][20][21][22][23][24][25] offering the advantage of strongly reduced thermal conductivity compared to metal gates. This is of high potential interest for solid-state cooling applications, where the ability to control disorder and set an optimal operation point using a gate, may enable optimization of the Using Polymer Electrolyte Gates to Set-and-Freeze Threshold Voltage and Local Potential in Nanowire-based Devices and Thermoelectrics Sofi a Fahlvik Svensson , Adam M. Burke , Damon J. Carrad , Martin Leijnse , Heiner Linke , and Adam P. Micolich * The strongly temperature-dependent ionic mobility in polymer electrolytes is used to "freeze in" specifi c ionic charge environments around a nanowire using a local wrap-gate geometry. This makes...

show abstract

Lineshape of the thermopower of quantum dots

Cited by 77 publications

References 27 publications

Thermoelectric energy harvesting with quantum dots

Thermoelectric energy harvesting with quantum dots

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

Using Polymer Electrolyte Gates to Set‐and‐Freeze Threshold Voltage and Local Potential in Nanowire‐based Devices and Thermoelectrics

Contact Info

Product

Resources

About