What Is Measured in the Scanning Gate Microscopy of a Quantum Point Contact?

Jalabert, Rodolfo A.; Szewc, Wojciech; Tomsovic, Steven; Weinmann, Dietmar

doi:10.1103/physrevlett.105.166802

Cited by 47 publications

(86 citation statements)

References 22 publications

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“…The λ F /2-periodic oscillations characteristic of g (1) 1 [21,22] are also present in the nonlinear conductance corrections, with a phase shift building up at large distances. This phase shift could be related with the well-defined phase conditions observed as a function of V in the difference of conductance changes between two tip positions [7].…”

Section: Fig 3 (Color Online) (Top)mentioning

confidence: 99%

“…For a QPC r m t m = 0 on a conductance plateau [21,22], yielding a vanishing μ. Moreover, away from the edges of the plateau the V and U derivatives of r m t m also vanish, and thus 115414-2 g (1) i = 0.…”

Section: Scanning-gate Effects On Transport Coefficientsmentioning

confidence: 99%

“…According to Ref. [21], the tip-induced changes in the conductance coefficients g (1) i are obtained when T in Eq. (2) is replaced by…”

Section: Scanning-gate Effects On Transport Coefficientsmentioning

confidence: 99%

“…Even in the linear regime, the interpretation of the resulting scans is delicate [21,22]. On one hand, from various experimental and theoretical works focused on a QPC probed by a strongly charged tip, the conductance change appears to be closely related to the local current density [15,16,23,24].…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, what is the local potential of a QPC operating in the nonlinear regime [1,[25][26][27][28][29]? Secondly, what is actually measured in the scanning gate microscopy of a QPC in the linear and nonlinear regimes [13,18,21,22]?…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Scanning-gate-induced effects in nonlinear transport through nanostructures

Gorini¹,

Weinmann²,

Jalabert³

2014

Phys. Rev. B

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We investigate the effect of a scanning gate tip on the nonlinear quantum transport properties of nanostructures. Generally, we predict that the symmetry of the current-voltage characteristic in reflection-symmetric samples is broken by a tip-induced rectifying conductance correction. Moreover, in the case of a quantum point contact (QPC), the tip-induced rectification term becomes dominant as compared to the change of the linear conductance at large tip-QPC distances. Calculations for a weak tip probing a QPC modeled by an abrupt constriction show that these effects are experimentally observable.

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Section: Fig 3 (Color Online) (Top)mentioning

confidence: 99%

Section: Scanning-gate Effects On Transport Coefficientsmentioning

confidence: 99%

“…According to Ref. [21], the tip-induced changes in the conductance coefficients g (1) i are obtained when T in Eq. (2) is replaced by…”

Section: Scanning-gate Effects On Transport Coefficientsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Scanning-gate-induced effects in nonlinear transport through nanostructures

Gorini¹,

Weinmann²,

Jalabert³

2014

Phys. Rev. B

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Quantum Sensing of Thermoelectric Power in Low‐Dimensional Materials

et al. 2022

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Thermoelectric power, has been extensively studied in low‐dimensional materials where quantum confinement and spin textures can largely modulate thermopower generation. In addition to classical and macroscopic values, thermopower also varies locally over a wide range of length scales, and is fundamentally linked to electron wave functions and phonon propagation. Various experimental methods for the quantum sensing of localized thermopower have been suggested, particularly based on scanning probe microscopy. Here, critical advances in the quantum sensing of thermopower are introduced, from the atomic to the several‐hundred‐nanometer scales, including the unique role of low‐dimensionality, defects, spins, and relativistic effects for optimized power generation. Investigating the microscopic nature of thermopower in quantum materials can provide insights useful for the design of advanced materials for future thermoelectric applications. Quantum sensing techniques for thermopower can pave the way to practical and novel energy devices for a sustainable society.

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Current density analysis of electron transport through molecular wires in open quantum systems

Nozaki

Schmidt

2017

J Comput Chem

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The current density in molecular wires connected to contacts is investigated within the nonequilibrium Green's function formalism combined with the Landauer approach. Energy-dependent and total current density through a series of molecular junctions are calculated in real space representation. A rich variety of current patterns including pronounced ring currents ("vortices") are found even in the defect-free minimal building blocks of molecular devices. The influences of contact positions, functional groups as well as atomic defects on the transport properties are examined systematically for prototypical ortho-, meta-, and para-substituted benzenes as well as heteroaromatic systems. It is found that substitutional functional groups mainly shift the molecular levels and retain characteristic transport channels, while a significant change of electronic pathways and conductance is induced by hetero-aromaticity. The current distribution is used to calculate the static magnetic field distribution in the carbon-based conductors. © 2017 Wiley Periodicals, Inc.

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What Is Measured in the Scanning Gate Microscopy of a Quantum Point Contact?

Cited by 47 publications

References 22 publications

Scanning-gate-induced effects in nonlinear transport through nanostructures

Scanning-gate-induced effects in nonlinear transport through nanostructures

Quantum Sensing of Thermoelectric Power in Low‐Dimensional Materials

Current density analysis of electron transport through molecular wires in open quantum systems

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