Formation and manipulation of a metallic wire of single gold atoms

The continuing miniaturization of microelectronics raises the prospect of nanometre-scale devices with mechanical and electrical properties that are qualitatively different from those at larger dimensions. The investigation of these properties, and particularly the increasing influence of quantum effects on electron transport, has therefore attracted much interest. Quantum properties of the conductance can be observed when ‘breaking’ a metallic contact: as two metal electrodes in contact with each other are slowly retracted, the contact area undergoes structural rearrangements until it consists in its final stages of only a few bridging atoms. Just before the abrupt transition to tunnelling occurs, the electrical conductance through a monovalent metal contact is always close to a value of 2e2/h (≈12.9 Ω−1), where e is the charge on an electron and h is Planck's constant. This value corresponds to one quantum unit of conductance, thus indicating that the ‘neck’ of the contact consists of a single atom. In contrast to previous observations of only single-atom necks, here we 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. Once we start to pull out a chain, the conductance never exceeds 2e2/h, confirming that it acts as a one-dimensional quantized nanowire. Given their high stability and the ability to support ballistic electron transport, these structures seem well suited for the investigation of atomic-scale electronics.

[1]  J. M. Ruitenbeek Quantum Point Contacts Between Metals , 1997 .

[2]  R. Landauer Spatial variation of currents and fields due to localized scatterers in metallic conduction , 1988 .

[3]  C. Muller,et al.  Experimental observation of the transition from weak link to tunnel junction , 1992 .

[4]  Juan Carlos Cuevas,et al.  The signature of chemical valence in the electrical conduction through a single-atom contact , 1998, Nature.

[5]  García,et al.  Quantum contact in gold nanostructures by scanning tunneling microscopy. , 1993, Physical review letters.

[6]  Sutton,et al.  Conditions for conductance quantization in realistic models of atomic-scale metallic contacts. , 1995, Physical review. B, Condensed matter.

[7]  Michel Devoret,et al.  Adjustable nanofabricated atomic size contacts , 1996 .

[8]  Sutton,et al.  Jumps in electronic conductance due to mechanical instabilities. , 1993, Physical review letters.

[9]  Uzi Landman,et al.  Atomistic Mechanisms and Dynamics of Adhesion, Nanoindentation, and Fracture , 1990, Science.

[10]  Karsten Wedel Jacobsen,et al.  Mechanical deformation of atomic-scale metallic contacts: Structure and mechanisms , 1998 .

[11]  K. Jacobsen,et al.  Conductance eigenchannels in nanocontacts , 1997 .

[12]  I. R. Mcdonald,et al.  ATOMISTIC SIMULATION OF THE STRETCHING OF NANOSCALE METAL WIRES , 1997 .

[13]  N. D. Lang ANOMALOUS DEPENDENCE OF RESISTANCE ON LENGTH IN ATOMIC WIRES , 1997 .

[14]  Vieira,et al.  Conductance steps and quantization in atomic-size contacts. , 1993, Physical review. B, Condensed matter.

[15]  Ali Yazdani,et al.  Off-Resonance Conduction Through Atomic Wires , 1996, Science.

[16]  Transport in a One-Dimensional Luttinger Liquid , 1996, cond-mat/9610037.

[17]  J. Pethica,et al.  Inelastic flow processes in nanometre volumes of solids , 1990 .

[18]  Muller,et al.  One-atom point contacts. , 1993, Physical review. B, Condensed matter.

[19]  Uzi Landman,et al.  Cluster-derived structures and conductance fluctuations in nanowires , 1997, Nature.

[20]  Laurits Højgaard Olesen,et al.  Quantized conductance in atom-sized wires between two metals. , 1995, Physical review. B, Condensed matter.

[21]  L. Sohn,et al.  Mesoscopic electron transport , 1997 .

[22]  K. Takayanagi,et al.  GOLD NANOBRIDGE STABILIZED BY SURFACE STRUCTURE , 1997 .

[23]  Vieira,et al.  Atomic-sized metallic contacts: Mechanical properties and electronic transport. , 1996, Physical review letters.

[24]  Hilla Peretz,et al.  Ju n 20 03 Schrödinger ’ s Cat : The rules of engagement , 2003 .