What is the reason for the nonlinear curves?

Redistribution subject toneling model and suggest that these are due to tunneling through a contaminant layer between the electrodes.

What is the conductance of a single-atom Au contact?

This suggests that the conductance of a single-atom Au contact ~which has a conductance close to G0)3,4 is almost independent of voltage.

What is the effect of the decrease of one of the main channel transmissions?

The authors find that the The author– V curve is very linear for the one-atom contact and has a slight down bend for the two-atom contact which is caused mainly by the decrease of one of the main channel transmissions below the Fermi energy (EF):

What is the current voltage of gold quantum point contacts?

@S0003-6951~00!02530-4#With the ongoing quest of miniaturizing electronic components, there is an increasing interest in fabricating and controlling atomic-scale quantum devices such as metallic quantum point contacts ~QPCs!.1–4

How can the authors fit the nonlinear curves to a tun-a?

the authors use a setup,10 whereby an The author– V curve can be acquired within only 20 ms, and transient contact geometries can be studied.

How many channels are there in the The author– V curve?

Although there are substantial variationsin the transmissions, only modest variations are seen in the The author– V curve, since the total transmission is found by averaging the sum of individual channel transmissions over the voltage window @EF2eV/2; EF1eV/2# .

What is the transmissions versus energy for the two-atom contact?

The transmissions versus energy for the two-atom contact are shown in the panels to the right in Fig. 3 for 0 and 1.5 V. For 0 V the authors find a conductance slightly below 2 G0 which is dominated by two channels with high transmissions $0.95,0.91,0.01,0.01%.

What is the contaminant layer in Fig. 2?

In hard indentations, the thin contaminant layer is likely to be destroyed, as evidenced by the preference for quantized values of the low-bias conductance in Fig.

What is the simplest explanation for the high stability of these contacts?

This readily explains the high stability of these contacts, the continuous distribution of G in Fig. 2, and the fact that they can sustain larger voltages than metallic contacts @cf.

Open AccessJournal Article10.1063/1.127093

Current-voltage curves of gold quantum point contacts revisited

K. Hansen, +5 more

- 27 Jul 2000

- Applied Physics Letters

- Vol. 77, Iss: 5, pp 708-710

101

TL;DR: In this article, measurements of current-voltage (I-V) curves on gold quantum point contacts (QPCs) with a conductance up to 4 G0 (G0=2e2/h is the conductance quantum) and voltages up to 2 V. The QPCs are formed between the gold tip of a scanning tunneling microscope and a Au(110) surface under clean ultrahigh-vacuum conditions at room temperature.

Abstract: We present measurements of current–voltage (I–V) curves on gold quantum point contacts (QPCs) with a conductance up to 4 G0 (G0=2e2/h is the conductance quantum) and voltages up to 2 V. The QPCs are formed between the gold tip of a scanning tunneling microscope and a Au(110) surface under clean ultra-high-vacuum conditions at room temperature. The I–V curves are found to be almost linear in contrast to previous reports. Tight-binding calculations of I–V curves for one- and two-atom contacts are in excellent agreement with our measurements. On the other hand, clearly nonlinear I–V curves are only observed when the sample has been cleaned in air.

AI Agents for this Paper

Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps

Most frequently asked questions

1. How many nonlinear terms are found in the The author– V curves?

About 80% of the The author– V curves obtained from soft indentations on a rinsed sample have nonlinear terms which exceed 0.2 G0 /V 2 and arbitrary values of G.

2. What is the transmission coefficient of the two-atom contact?

Since transmission coefficients in tunneling are orders of magnitudes smaller than those typically encountered in metallic conduction, the contact area needed to reach a conductance of a few G0 will be much larger than atomic dimensions.

3. How can the authors stabilize contacts formed in soft indentations?

@The authors can only stabilize contacts formed in soft indentations on a sputtered and annealed surface with a conductance smaller than 4 G0 by cooling the sample to approximately 2100 °C.

4. What are the common examples of The author– V curves?

They are almost linear if the sample is sputtered and annealed or the contacts are formed by hard indentations @curves ~a! and ~b!#.

FIG. 2. Nonlinear termG9 vs low-bias conductanceG obtained by fitting measuredI –V curves to Eq.~1! for different sample preparation/contac formation techniques. Only fits to nearly polarity independentI –V curves (uG8u,0.05G/V) with small uncertainties of the cubic term (sG9 ,0.01G/V2) are shown. Numbers in parenthesis indicate the numbe I –V curves.

FIG. 1. Examples of measuredI –V curves of Au contacts formed at RT using different sample preparation/contact formation techniques. Each c is acquired during 20ms ~a single period of a 50 kHz triangular voltag burst! and consists of 2000 data points. Best fits to Eq.~1! ~dashed lines! give the following values of (G, G8, G9) in units of (G0 , G0 /V, G0 /V 2): ~a! ~1.95,20.08, 0.07!; ~b! ~1.91, 0.07,20.05!; and~c! ~1.72,20.02, 0.59!. Individual I –V curves are shifted by 100mA for clarity.

FIG. 4. Solid lines: examples of experimentalI –V curves obtained from soft indentaions on a rinsed sample. Dotted lines: fits to the parabolic ba model sketched in the inset~see Ref. 13! assuming a barrier heightf0 2EF51.5 eV and a temperature of 300 K. Fitted values of the bar thicknessd and contact radiusr are given in the figure.

Citations

•Journal Article•10.1103/PHYSREVB.65.165401

Density-functional method for nonequilibrium electron transport

Mads Brandbyge, +4 more

- 22 Mar 2002

- Physical Review B

TL;DR: In this paper, an ab initio method for calculating the electronic structure, electronic transport, and forces acting on the atoms, for atomic scale systems connected to semi-infinite electrodes and with an applied voltage bias.

...read moreread less

5.6K

•Journal Article•10.1016/S0370-1573(02)00633-6

Quantum properties of atomic-sized conductors

Nicolás Agraït, +2 more

- 01 Apr 2003

- Physics Reports

TL;DR: In this article, the authors discuss the results in the context of related developments, including Andreev reflection, shot noise, conductance quantization and dynamical Coulomb blockade.

...read moreread less

1.6K

Journal Article•10.1088/0953-8984/14/11/314

Tight-binding simulation of current-carrying nanostructures

Tchavdar N. Todorov

- 25 Mar 2002

- Journal of Physics: Condensed Matter

TL;DR: In this article, the authors introduced the tight binding approach to the modeling of electrical conduction in small structures and derived different equivalent forms of the tight-binding expression for the electrical current in a nanoscale junction.

...read moreread less

175

•Journal Article•10.1103/PHYSREVB.77.155401

Atomic configuration and mechanical and electrical properties of stable gold wires of single-atom width

Tokushi Kizuka

- 01 Apr 2008

- Physical Review B

TL;DR: In this article, the formation dynamics of stable gold wires of single-atom width during tensile deformation of the nanometer-sized Au contacts was observed in situ at room temperature by transmission electron microscopy.

...read moreread less

169

TranSIESTA: A SPICE for Molecular Electronics

Mads Brandbyge, +3 more

- 23 Feb 2003

163

...

Expand

References

Journal Article•10.1038/27399

Quantized conductance through individual rows of suspended gold atoms

Hideaki Ohnishi, +2 more

- 22 Oct 1998

- Nature

TL;DR: In this article, the authors measured the conductance of a single strand of gold atoms with an STM and a double strand with an ultrahigh-vacuum electron microscope.

...read moreread less

1.4K

•Journal Article•10.1038/27405

Formation and manipulation of a metallic wire of single gold atoms

A. I. Yanson, +4 more

- 01 Oct 1998

- Nature

TL;DR: In this article, the authors describe the breaking of atomic-scale gold contacts, which leads to the formation of gold chains one atom thick and at least four atoms long, confirming that the conductance never exceeds 2e2/h, thus indicating that the neck of the contact consists of a single atom.

...read moreread less

871

of a metallic wire of single gold atoms

A. I. Yanson, +3 more

- 01 Jan 1998

698

Journal Article•10.1126/SCIENCE.253.5021.776

Contact Adhesion of Thin Gold Films on Elastomeric Supports: Cold Welding Under Ambient Conditions

Gregory S. Ferguson, +3 more

- 16 Aug 1991

- Science

TL;DR: Thin gold films placed in contact on compliant elastomeric poly(dimethylsiloxane) supports weld together, and this ``cold welding'' is remarkable both for the low loads required and for the fact that it occurs under ambient laboratory conditions.

...read moreread less

207

Journal Article•10.1063/1.120754

Fabrication of quantum devices by Ångström-level manipulation of nanoparticles with an atomic force microscope

T. Junno, +4 more

- 04 Jun 1998

- Applied Physics Letters

TL;DR: In this article, a technique for the fabrication of lateral nanometer-scale devices is described, in which individual metallic nanoparticles are imaged, selected and manipulated into a gap between two electrical leads with the tip of an atomic force microscope.

...read moreread less

Current-voltage curves of gold quantum point contacts revisited

Chat with Paper

AI Agents for this Paper

Most frequently asked questions

1. How many nonlinear terms are found in the The author– V curves?

2. What is the transmission coefficient of the two-atom contact?

3. How can the authors stabilize contacts formed in soft indentations?

4. What are the common examples of The author– V curves?

5. What is the reason for the nonlinear curves?

6. What is the conductance of a single-atom Au contact?

7. What is the effect of the decrease of one of the main channel transmissions?

8. What is the current voltage of gold quantum point contacts?

9. How can the authors fit the nonlinear curves to a tun-a?

10. How many channels are there in the The author– V curve?

11. What is the transmissions versus energy for the two-atom contact?

12. What is the contaminant layer in Fig. 2?

13. What is the simplest explanation for the high stability of these contacts?

Figures

Citations

Density-functional method for nonequilibrium electron transport

Quantum properties of atomic-sized conductors

Tight-binding simulation of current-carrying nanostructures

Atomic configuration and mechanical and electrical properties of stable gold wires of single-atom width

TranSIESTA: A SPICE for Molecular Electronics

References

Quantized conductance through individual rows of suspended gold atoms

Formation and manipulation of a metallic wire of single gold atoms

of a metallic wire of single gold atoms

Contact Adhesion of Thin Gold Films on Elastomeric Supports: Cold Welding Under Ambient Conditions

Fabrication of quantum devices by Ångström-level manipulation of nanoparticles with an atomic force microscope

Related Papers (5)

Quantum properties of atomic-sized conductors

Quantized conductance through individual rows of suspended gold atoms

The signature of conductance quantization in metallic point contacts

Formation and manipulation of a metallic wire of single gold atoms

The signature of chemical valence in the electrical conduction through a single-atom contact