Transmission eigenchannels for coherent phonon transport

Klöckner, Jan C.; Cuevas, Juan Carlos; Pauly, Fabian

doi:10.1103/physrevb.97.155432

Cited by 22 publications

(43 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For longer molecules more transmission resonances arise between 0 and E max , since more molecular modes overlap with the phonon density of states of Au. In addition, we find that for all junctions the transmission values are below 3, which, as we have discussed before 29 , is related to the linear, one-dimensional structure of the alkane molecules. Last, we note that anharmonic effects, which result in phonon-phonon scattering, could reduce heat flow.…”

supporting

confidence: 63%

“…Thermal conductance within the Landauer-Büttiker approach. To calculate the thermal conductance of molecular junctions, we employ the Landauer-Büttiker formalism for coherent transport 19,29,36,37 . This theory describes phonon transport as phase-coherent and elastic.…”

Section: Nanofabrication Of Scanning Thermal Probesmentioning

confidence: 99%

“…This theory describes phonon transport as phase-coherent and elastic. Since in this formalism transport is described as a scattering problem of waves, the key quantity is the probability τ ph (E) of a phonon at a given energy E to be transmitted from one lead to the other, which is computed using the procedures developed in our past work 15,29,31 . The linear response coefficient (G th,SMJ ) can be calculated using:…”

Section: Nanofabrication Of Scanning Thermal Probesmentioning

confidence: 99%

“…To elucidate the microscopic origin of our observations, we use the Landauer-Büttiker formalism for coherent transport 19,29 (see Methods). The respective junction geometry, for which the transmission plot is performed, is indicated by an arrow in the corresponding trace in a or b.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Thermal conductance of single-molecule junctions

Cui

Hur

Akbar

et al. 2019

Nature

167

157

View full text Add to dashboard Cite

Single-molecule junctions have been extensively used to probe properties as diverse as electrical conduction 1-3 , light emission 4 , thermoelectric energy conversion 5,6 , quantum interference 7,8 , heat dissipation 9,10 and electronic noise 11 at atomic and molecular scales. However, a key quantity of current interest-the thermal conductance of single-molecule junctions-has not yet been directly experimentally determined, owing to the challenge of detecting minute heat currents at the picowatt level. Here we show that picowatt-resolution scanning probes previously developed to study the thermal conductance of single-metal-atom junctions 12 , when used in conjunction with a time-averaging measurement scheme to increase the signal-to-noise ratio, also allow quantification of the much lower thermal conductance of single-molecule junctions. Our experiments on prototypical Au-alkanedithiol-Au junctions containing two to ten carbon atoms confirm that thermal conductance is to a first approximation independent of molecular length, consistent with detailed ab initio simulations. We anticipate that our approach will enable systematic exploration of thermal transport in many other one-dimensional systems, such as short molecules and polymer chains, for which computational predictions of thermal conductance 13-16 have remained experimentally inaccessible.Studies of charge and heat transport in molecules are of great fundamental interest, and are of critical importance for the development of a variety of technologies, including molecular electronics 17 , thermally conductive polymers 18 and thermoelectric energy-conversion devices 19 . Given this overall importance and the daunting experimental challenges, a number of initial studies explored charge transport in ensembles of molecules 20,21 . Although such measurements provided important insights, researchers gradually began to realize that it was

show abstract

supporting

confidence: 63%

Section: Nanofabrication Of Scanning Thermal Probesmentioning

confidence: 99%

Section: Nanofabrication Of Scanning Thermal Probesmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Thermal conductance of single-molecule junctions

Cui

Hur

Akbar

et al. 2019

Nature

167

157

View full text Add to dashboard Cite

show abstract

“…In particular, the inefficiency of phonon transfer within a network of conductive particles in contact has been related to the "soft" interface, which does not allow transfer of efficient vibrational modes of phonons 7,20 . A possible approach to decrease this contact resistance is by grafting molecular junctions 21 between nanoparticles, to increase the contact stiffness and enhance phonon transfer [22][23] .…”

Section: Introductionmentioning

confidence: 99%

Aromatic molecular junctions between graphene sheets: a molecular dynamics screening for enhanced thermal conductance

et al. 2019

View full text Add to dashboard Cite

The proper design and synthesis of molecular junctions for the purpose of establishing percolative networks of conductive nanoparticles represent an opportunity to develop more efficient thermallyconductive nanocomposites, with several potential applications in heat management. In this work, theoretical classical molecular dynamics simulations were conducted to design and evaluate thermal conductance of various molecules serving as thermal bridges between graphene nanosheets. A wide range of molecular junctions was studied, with a focus on the chemical structures that are viable to synthesize at laboratory scale. Thermal conductances were correlated with the length and mechanical stiffness of the chemical junctions. The simulated tensile deformation of the molecular junction revealed that the mechanical response is very sensitive to small differences in the chemical structure. The analysis of the vibrational density of states provided insights into the interfacial vibrationalproperties. A knowledge-driven design of the molecular junction structures is proposed, aiming at controlling interfacial thermal transport in nanomaterials. This approach may allow for the design of more efficient heat management in nanodevices, including flexible heat spreaders, bulk heat exchangers and heat storage devices.©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

show abstract

Selective Transmission of Phonons in Molecular Junctions with Nanoscopic Thermal Baths

et al. 2019

View full text Add to dashboard Cite

A fundamental problem for thermal energy harvesting is the development of atomistic design strategies for smart nanodevices and nanomaterials that can be used to selectively transmit heat. We carry out here an extensive computational study demonstrating that heterogeneous molecular junctions, consisting of molecular wires bridging two different nanocontacts, can act as a selective phonon filter. The most important finding is the appearance of gaps on the phonon transmittance spectrum, which are strongly correlated to the properties of the vibrational spectrum of the specific molecular species in the junction. The filtering effect results from a delicate interplay between the intrinsic vibrational structure of the molecular chains and the different Debye cutoffs of the nanoscopic electrodes used as thermal baths.

show abstract

Transmission eigenchannels for coherent phonon transport

Cited by 22 publications

References 72 publications

Thermal conductance of single-molecule junctions

Thermal conductance of single-molecule junctions

Aromatic molecular junctions between graphene sheets: a molecular dynamics screening for enhanced thermal conductance

Selective Transmission of Phonons in Molecular Junctions with Nanoscopic Thermal Baths

Contact Info

Product

Resources

About