Advanced Simulation of Conductance Histograms Validated through Channel-Sensitive Experiments on Indium Nanojunctions

Makk, Péter; Visontai, Dávid; Oroszlány, László; Manrique, David Zsolt; Csonka, Szabolcs; Cserti, József; Lambert, Colin J.; Halbritter, András

doi:10.1103/physrevlett.107.276801

Cited by 21 publications

(23 citation statements)

References 26 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In atomic scale conductors, electrical current is transmitted through discrete conduction channels that are dominated by the orbital structure of the conductor [1][2][3][4][5][6][7][8][9][10] . The importance of studying conductance phenomena in view of orbital structure is illustrated by the case of single atom contacts 1 .…”

Section: Main Textmentioning

confidence: 99%

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

et al. 2014

View full text Add to dashboard Cite

We investigate periodical oscillations in the conductance of suspended Au and Pt atomic chains during elongation under mechanical stress. Analysis of conductance and shot noise measurements reveals that the oscillations are mainly related to variations in a specific conduction channel as the chain undergoes transitions between zigzag and linear atomic configurations. The calculated local electronic structure shows that the oscillations originate from varying degrees of hybridization between the atomic orbitals along the chain as a function of the zigzag angle. These variations are highly dependent on the directionality and symmetry of the relevant orbitals, in agreement with the order-of-magnitude difference between the Pt and Au oscillation amplitudes observed in experiment. Our results demonstrate that the sensitivity of conductance to structural variations can be controlled by designing atomic-scale conductors in view of the directional interactions between atomic orbitals

show abstract

Section: Main Textmentioning

confidence: 99%

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The challenges of atomic point contacts have been addressed by various approaches, including the break-junction method [2][3][4][5], transmission electron microscopy [6], and scanning tunneling microscopy (STM) [7][8][9][10][11][12][13][14][15], as well as in theoretical calculations [16][17][18][19][20][21][22].…”

mentioning

confidence: 99%

Site-Dependent Evolution of Electrical Conductance from Tunneling to Atomic Point Contact

Kim

Hasegawa

2015

Phys. Rev. Lett.

View full text Add to dashboard Cite

Using scanning tunneling microscopy (STM), we investigated the evolution of electrical conductance between a Pb tip and Pb(111) surface from tunneling to atomic point contact at a site that was defined with atomic precision. We found that the conductance evolution depended on the contact site, for instance, on-top, bridge, or hollow (hcp and fcc) sites in the Pb lattice. In the transition from tunneling to contact regimes, the conductance measured at the on-top site was enhanced. In the point contact regime, the hollow sites had conductances larger than those of the other sites, and between the hollow sites, the hcp site had a conductance larger than that of the fcc site. We also observed the enhancement and reversal of the apparent height in atomically resolved high-current STM images, consistent with the results of the conductance traces. Our

show abstract

“…Recently, some of the above codes have been combined with classical force field programs, enabling the simulation of much larger systems and the sampling of a much wider set of atomic arrangements. 13,14 Nevertheless, present current-voltage I -V characteristics are still computed using NEGF techniques, which are rather cumbersome and extremely computer hungry. In other words, the NEGF is a serious bottleneck hindering the deployment of realistic transport simulations at the nanoscale.…”

mentioning

confidence: 99%

Nonequilibrium transport response from equilibrium transport theory

García‐Suárez

Ferrer

2012

Phys. Rev. B

View full text Add to dashboard Cite

We propose a simple scheme that describes accurately essential nonequilibrium effects in nanoscale electronics devices using equilibrium transport theory. The scheme, which is based on the alignment and dealignment of the junction molecular orbitals with the shifted Fermi levels of the electrodes, simplifies drastically the calculation of current-voltage characteristics compared to typical nonequilibrium algorithms. We probe that the scheme captures a number of nontrivial transport phenomena such as the negative differential resistance and rectification effects. It applies to those atomic-scale junctions whose relevant states for transport are spatially placed on the contact atoms or near the electrodes. Nanoscale devices tend to suffer from a serious lack of reproducibility from one research group to another, and from a lack of durability and robustness. 1,2 However, the consistent and thorough work of a range of experimental groups has allowed researchers to reach some consensus on the conductance values and variability of a few specific junctions. [3][4][5] In addition, the development of simulation codes based on a combination of density functional theory (DFT) and the nonequilibrium Green's function formalism (NEGF) [5][6][7][8][9][10][11][12] has enabled theoreticians to assist the above experiments with theoretical insights and predictions. However, the size and complexity of the experimentally active part of the junction is typically too large, and the above codes need to assume a number of simplifications regarding the size, geometry, number of feasible atomic arrangements, and the electronic correlations. Recently, some of the above codes have been combined with classical force field programs, enabling the simulation of much larger systems and the sampling of a much wider set of atomic arrangements. 13,14 Nevertheless, present current-voltage I -V characteristics are still computed using NEGF techniques, which are rather cumbersome and extremely computer hungry. In other words, the NEGF is a serious bottleneck hindering the deployment of realistic transport simulations at the nanoscale. In contrast, equilibrium transport techniques are much simpler, better founded on physical grounds, and computationally drastically less demanding. 6 However, they are completely unable to reproduce current-voltage curves of nanoscale devices. 15 This is so because these techniques assume that the electronic states and the Hamiltonian at the junction do not change under the application of a voltage. However, a voltage bias drives a flow of electrons into and out of the junction, driving the device out of equilibrium and possibly even changing its quantum state and sometimes even its atomic arrangement. For example, the electric field originated by the voltage bias can also shift the energy position of the molecular levels by the Stark effect, depending on the polarizability of each molecular level or on whether the molecule has itself a polar nature. 16,17 We show here a suitable modification of equilibrium transport te...

show abstract

Advanced Simulation of Conductance Histograms Validated through Channel-Sensitive Experiments on Indium Nanojunctions

Cited by 21 publications

References 26 publications

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

Probing the Orbital Origin of Conductance Oscillations in Atomic Chains

Site-Dependent Evolution of Electrical Conductance from Tunneling to Atomic Point Contact

Nonequilibrium transport response from equilibrium transport theory

Contact Info

Product

Resources

About