اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدAtomic resolution STM imaging of a twisted single-wall carbon nanotube
96
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We present atomically-resolved STM images of single-wall carbon nanotubes (SWNTs) embedded in a crystalline nanotube rope. Although they may be interpreted as of a chiral nanotube, the images are more consistently explained a an achiral armchair tube with a quenched twist distortion. The existence of quenched twists in SWNTs in ropes might explain the fact that both as-grown bulk nanotube material and individual ropes have insulator-like conductivity at low temperature.
قيم البحث
اقرأ أيضاً
We have reproducibly contacted gated single wall carbon nanotubes (SWCNT) to superconducting leads based on niobium. The devices are identified to belong to two transparency regimes: The Coulomb blockade and the Kondo regime. Clear signature of the s
uperconducting leads is observed in both regimes and in the Kondo regime a narrow zero bias peak interpreted as a proximity induced supercurrent persist in Coulomb blockade diamonds with Kondo resonances.
Electronic transport through a single-wall metallic carbon nanotube weakly coupled to one ferromagnetic and one nonmagnetic lead is analyzed in the sequential tunneling limit. It is shown that both the spin and charge currents flowing through such sy
stems are highly asymmetric with respect to the bias reversal. As a consequence, nanotubes coupled to one nonmagnetic and one ferromagnetic lead can be effectively used as spin diodes whose functionality can be additionally controlled by a gate voltage.
We observe current rectification in a molecular diode consisting of a semiconducting single-wall carbon nanotube and an impurity. One half of the nanotube has no impurity, and it has a current-voltage (I-V) charcteristic of a typical semiconducting n
anotube. The other half of the nanotube has the impurity on it, and its I-V characteristic is that of a diode. Current in the nanotube diode is carried by holes transported through the molecules one-dimensional subbands. At 77 Kelvin we observe a step-wise increase in the current through the diode as a function of gate voltage, showing that we can control the number of occupied one-dimensional subbands through electrostatic doping.
A top-gated single wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements of single,
double and triple quantum dot stability diagrams. Simulations using a capacitor model including tunnel coupling between neighboring dots captures the observed behavior with good agreement. Furthermore, anti-crossings between indirectly coupled levels and higher order cotunneling are discussed.
We describe a method to fabricate clean suspended single-wall carbon nanotube (SWCNT) transistors hosting a single quantum dot ranging in length from a few 10s of nm down to $approx$ 3 nm. We first align narrow gold bow-tie junctions on top of indivi
dual SWCNTs and suspend the devices. We then use a feedback-controlled electromigration to break the gold junctions and expose nm-sized sections of SWCNTs. We measure electron transport in these devices at low temperature and show that they form clean and tunable single-electron transistors. These ultra-short suspended transistors offer the prospect of studying THz oscillators with strong electron-vibron coupling.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
