Characterizing destructive quantum interference in electron transport

Sam-ang, Panu; Reuter, Matthew G.

doi:10.1088/1367-2630/aa6c23

Cited by 18 publications

(12 citation statements)

References 47 publications

(103 reference statements)

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“…A similar condition was recently analyzed in the context of destructive quantum interferences. 18,19 The density of states of the open quantum system is…”

Section: Energy Spectrummentioning

confidence: 99%

The third law of thermodynamics in open quantum systems

Shastry

Stafford

2019

The Journal of Chemical Physics

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We consider open quantum systems consisting of a finite system of independent fermions with arbitrary Hamiltonian coupled to one or more equilibrium fermion reservoirs (which need not be in equilibrium with each other). A strong form of the third law of thermodynamics, S(T ) → 0 as T → 0, is proven for fully open quantum systems in thermal equilibrium with their environment, defined as systems where all states are broadened due to environmental coupling. For generic open quantum systems, it is shown that S(T ) → g ln 2 as T → 0, where g is the number of localized states lying exactly at the chemical potential of the reservoir. For driven open quantum systems in a nonequilibrium steady state, it is shown that the local entropy S(x; T ) → 0 as T (x) → 0, except for cases of measure zero arising due to localized states, where T (x) is the temperature measured by a local thermometer.

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“…A similar condition was recently analyzed in the context of destructive quantum interferences. 18,19 The density of states of the open quantum system is…”

Section: Energy Spectrummentioning

confidence: 99%

The third law of thermodynamics in open quantum systems

Shastry

Stafford

2019

The Journal of Chemical Physics

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“…It should be noted that previous studies on quantum interference in electron transport focused on different geometrical conformations or connections of molecules to nonmagnetic electrodes [18][19][20][21][22] . The mostly discussed effect is, for example, the destructive quantum interference occurring when the benzene molecule is connected to electrodes in meta or ortho configuration contrary to the para orientation 18,19,23 .…”

Section: Introductionmentioning

confidence: 99%

Symmetry aspects of spin filtering in molecular junctions: Hybridization and quantum interference effects

Banerjee

Mondal

et al. 2019

Phys. Rev. B

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Control and manipulation of electric current and, especially, its degree of spin polarization (spin filtering) across single molecules are currently of great interest in the field of molecular spintronics. We explore one possible strategy based on the modification of nanojunction symmetry which can be realized, for example, by a mechanical strain. Such modification can activate new molecular orbitals which were inactive before due to their orbital mismatch with the electrodes conduction states. This can result in several important consequences such as (i) quantum interference effects appearing as Fano-like features in electron transmission and (ii) the change in molecular level hybridization with the electrodes states. We argue that the symmetry change can affect very differently two majority-and minority-spin conductances and thus alter significantly the resulting spin-filtering ratio as the junction symmetry is modified.We illustrate the idea for two basic molecular junctions: Ni/benzene/Ni (perpendicular vs tilted orientations) and Ni/Si chain/Ni (zigzag vs linear chains). In both cases, one highest occupied molecular orbital (HOMO) and one lowest unoccupied molecular orbital (LUMO) (out of HOMO and LUMO doublets) are important. In particular, their destructive interference with other orbitals leads to dramatic suppression of majority-spin conductance in low-symmetry configurations. For a minorityspin channel, on the contrary, the conductance is strongly enhanced when the symmetry is lowered due to an increase in hybridization strength. We believe that our results may offer a potential route for creating molecular devices with a large on-off ratio of spin polarization via quantum interference effects.PACS numbers:

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“…Red, blue, and green dots in C represent nitrogen substitution position for each basis circuit in the TPo, TPm, and TPp breadboards, respectively. coherent electronic conductance in a variety of molecular junctions (22,(29)(30)(31)(32). Manrique et al (22) showed that the MCBJ and STM-BJ conductance in pyridyl-terminated oligo(phenyleneethynylene) molecules with meta N atoms is lower than that with the para N atom connectivity.…”

Section: Introductionmentioning

confidence: 99%

Simultaneously Tuning the Conductance of Multiple Embedded Circuits in Bis-Terpyridine-Based Single Molecule Breadboard Junctions

Kumar

Seth

Kaliginedi

et al. 2022

Preprint

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Assembling and prototyping multiple circuits on a common breadboard scaffold is critical for developing functional single molecule electronic devices. However, at present, controlling and combining the electronic properties of multiple circuits within a single-molecule junction remains an unresolved challenge. Here, we describe the molecular conductance distributions for five single terminal circuits each within three constitutional isomers of a bis-terpyridine-based molecular breadboard junction through a rigorous computational framework which accounts for molecular conformational flexibility and the relative electrode accessibility (REA) of anchoring groups. The isomers, termed TPo, TPm, and TPp, differ in the relative placement of the linking nitrogen (N) atoms at ortho, meta, and para positions, respectively, of the peripheral pyridyl rings. We demonstrate that quantum interference effects (QIE) and REA of the anchoring N atoms can be exploited to alter the relative conductance of the five single terminal circuits within the molecular breadboards by ~ 4–32 times. We introduce a phase-plot-analysis to highlight the interdependence of QIE- and REA-induced changes in the conductance states of the basis circuits across breadboard pairs. Our studies predict that REA should not impact the QIE-induced boost in circuit conductance for TPp relative to that in TPm. In contrast, REA suppresses the QIE boost for circuit conductance in TPo relative to that in TPm. Our results showcase the possibility of accessing the combined effect of QIE and REA within an experimental break-junction setup to develop diverse molecular electronic breadboards with multiple embedded circuits and distinct electronic properties.

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Characterizing destructive quantum interference in electron transport

Cited by 18 publications

References 47 publications

The third law of thermodynamics in open quantum systems

The third law of thermodynamics in open quantum systems

Symmetry aspects of spin filtering in molecular junctions: Hybridization and quantum interference effects

Simultaneously Tuning the Conductance of Multiple Embedded Circuits in Bis-Terpyridine-Based Single Molecule Breadboard Junctions

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