اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدAluminium Nanowires: Influence of Work Hardening on Conductance Histograms
146
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Conductance histograms of work-hardened Al show a series up to 11 equidistant peaks with a period of 1.15 +/- 0.02 of the quantum conductance unit G_0 = 2e^2/h. Assuming the peaks originate from atomic discreteness, this agrees with the value of 1.16 G_0 per atom obtained in numerical calculations by Hasmy et al.
قيم البحث
اقرأ أيضاً
Nanowires of different nature have been shown to self-assemble as a function of stress at the contact between two macroscopic metallic leads. Here we demonstrate for gold wires that the balance between various metastable nanowire configurations is in
fluenced by the microstructure of the starting materials and we discover a new set of periodic structures, which we interpret as due to the atomic discreteness of the contact size for the three principal crystal orientations.
Aluminium oxide (AlO$_mathrm{x}$) tunnel junctions are important components in a range of nanoelectric devices including superconducting qubits where they can be used as Josephson junctions. While many improvements in the reproducibility and reliabil
ity of qubits have been made possible through new circuit designs, there are still knowledge gaps in the relevant materials science. A better understanding of how fabrication conditions affect the density, uniformity, and elemental composition of the oxide barrier may lead to the development of lower noise and more reliable nanoelectronics and quantum computers. In this paper we use molecular dynamics to develop models of Al-AlO$_mathrm{x}$-Al junctions by iteratively growing the structures with sequential calculations. With this approach we can see how the surface oxide grows and changes during the oxidation simulation. Dynamic processes such as the evolution of a charge gradient across the oxide, the formation of holes in the oxide layer, and changes between amorphous and semi-crystalline phases are observed. Our results are widely in agreement with previous work including reported oxide densities, self-limiting of the oxidation, and increased crystallinity as the simulation temperature is raised. The encapsulation of the oxide with metal evaporation is also studied atom by atom. Low density regions at the metal-oxide interfaces are a common feature in the final junction structures which persists for different oxidation parameters, empirical potentials, and crystal orientations of the aluminium substrate.
We present a complete numerical calculation and an experimental data analysis of the universal conductance fluctuations in quasi-one-dimension nanowires. The conductance peak density model, introduced in nanodevice research on [Phys. Rev. Lett. 107,
176807 (2011)], is applied successfully to obtain the coherence length of InAs nanowire magnetoconductance and we prove its equivalence with correlation methods. We show the efficiency of the method and therefore a prominent alternative to obtain the phase-coherence length. The peak density model can be similarly applied to spintronic setups, graphene and topological isolator where phase-coherence length is a relevant experimental parameter.
We study by means of density-functional calculations the role of lateral surface reconstructions in determining the electrical properties of <100> silicon nanowires. The different lateral reconstructions are explored by relaxing all the nanowires wit
h crystalline bulk silicon structure and all possible ideal facets that correspond to an average diameter of 1.5 nm. We show that the reconstruction induces the formation of ubiquitous surface states that turn the wires into semi-metallic or metallic.
Effect of contact interfaces, between metallic single-wall carbon nanotubes (SWCNT) and external electrodes made also of nanotubes, on the electrical conductance is studied. A tight-binding model with both diagonal and off-diagonal disorder, a recurs
ive Green function technique as well as the Landauer formalism are used. The studies are carried out within the coherent transport regime and are focused on: (i) evolution from conductance quantization to resonant tunneling, (ii) SWCNTs length effects and (iii) magnetoresistance. It is shown that the so-called on-resonance devices, i.e. nanotubes having a conductance peak at the Fermi energy, occur with a period of 3 carbon inter-ring spacings. Additionally, the present approach provides an insight into magnetoresistance dependence of SWCNTs on conditions at the contact interface.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
