Four-probe measurements of carbon nanotubes with narrow metal contacts

Makarovski, A.; Zhukov, А.; Liu, J.; Finkelstein, Gleb

doi:10.1103/physrevb.76.161405

Cited by 23 publications

(28 citation statements)

References 15 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this model the InAs wire is considered to be divided into two sequentially connected quantum dots. The next main parameters are used to characterize this system: dot 1(2) to back-gate capacitance (C 1(2)BG ), the mutual capacitance of the dots (C m ), and the capacitance of dot 1(2) to the left(right) contact (C L(R) ), the width of the energy levels of dot 1(2) (Γ 1 (2) ). The explicit expression of dot 1(2) to tip capacitance C 1(2)t on the tip to dot distance can be found in [31].…”

Section: Methodsmentioning

confidence: 99%

Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at liquid helium temperatures

et al. 2014

View full text Add to dashboard Cite

In the current paper a set of experiments dedicated to investigations of local electronic transport in undoped InAs nanowires at helium temperatures in the presence of a charged atomic-force microscope tip is presented. Both nanowires without defects and with internal tunneling barriers were studied. The measurements were performed at various carrier concentrations in the systems and opacity of contact-to-wire interfaces. The regime of Coulomb blockade is investigated in detail including negative differential conductivity of the whole system. The situation with open contacts with one tunneling barrier and undivided wire is also addressed. Special attention is devoted to recently observed quasi-periodic standing waves.

show abstract

Section: Methodsmentioning

confidence: 99%

Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at liquid helium temperatures

et al. 2014

View full text Add to dashboard Cite

show abstract

“…First, the straight way passing the second contact in the outermost shell directly below the electrode. Although Ke et al [126] calculated that the transmission straight through the contact is drastically decreasing even for narrow contacts, Makarovski et al [127] and Gunnarsson et al [128] both found a non-constant non-local potential in SWCNTs indicating a non-vanishing transmission through the contact. For the MWCNT used in our experiment, an additional pathway that does not cross the contact is possible.…”

Section: Measurements In Non-local Geometrymentioning

confidence: 99%

“…Another approach for these fluctuations is given by Makarovski et al [127] and Gunnarsson et al [128]. The authors found significant voltages in four-point measurements of SWCNTs in non-local geometry and traced it back to different coupling of the probes to the two orbital modes of the tube.…”

Section: Measurements In Non-local Geometrymentioning

confidence: 99%

Conductivity of multiwall carbon nanotubes: Role of multiple shells and defects

2010

View full text Add to dashboard Cite

“…Note: After completing this work, we have become aware of a similar, but independent study by A. Makarovski et al [23].…”

mentioning

confidence: 93%

“…The dashed curve is suppressed by approximately a factor of 7 − 8. Hence, a fraction of 13 % can pass under the contact by direct transmission [23]. This is surprisingly large taken the typical values of the two-terminal resistances and the fact that the metal electrodes were evaporated directly onto a freshly CVD-grown CNT.…”

mentioning

confidence: 99%

Large oscillating nonlocal voltage in multiterminal single-wall carbon nanotube devices

2008

View full text Add to dashboard Cite

We report on the observation of a non-local voltage in a ballistic (quasi) one-dimensional conductor, realized by a single-wall carbon nanotube with four contacts. The contacts divide the tube into three quantum dots which we control by the back-gate voltage Vg. We measure a large oscillating non-local voltage V nl as a function of Vg. Though a classical resistor model can account for a non-local voltage including change of sign, it fails to describe the magnitude properly. The large amplitude of V nl is due to quantum interference effects and can be understood within the scattering-approach of electron transport.PACS numbers: 73.23.Ad,73.63.Fg,73.63.Nm,73.63.Kv,72.80.Rj The recent realization of the spin field-effect transistor in carbon nanotube (CNT) devices [1] demonstrated the ability to control spin transport in a quantum dot (QD) [2]. However, additional effects, such as the anomalous magnetoresistance, can contribute to the observed signal in spin-valves [3,4,5,6]. It seems clear, that despite a number of large responses seen in CNT-based devices [1,7,8,9], one needs to go beyond two terminal structures by realizing multi-terminal devices where non-local measurements are feasible [10]. The non-local measurement in spin-valve devices has been pioneered by Johnson and Silsbee [11] in metallic spin-valves and was further applied to various other systems [12,13,14]. This technique separates spin from charge effects. Recent application of the non-local spin technique in CNTs [10] showed the feasibility and yet tremendous challenge of performing such measurements in low dimensional mesoscopic systems. The hallmark of these measurements is that a positive voltage is measured when the magnetization of the injector and detector electrodes are parallel and a negative only when they are antiparallel. However, it has been reported recently that the four-probe resistance with non-magnetic probes in CNTs can be negative due to interference effects [15]. This suggests that the measurement of the non-local spin transport in mesoscopic systems like CNTs with ferromagnetic contacts should be strongly influenced by quantum interference effects.We report here on measurements of a large non-local voltage V nl in multi-terminal CNT devices (Fig. 1a) in the quantum-dot (QD) regime which changes sign and magnitude as the back-gate voltage is swept. We show that V nl cannot be explained by a classical resistor model. Instead, a quantum approach is required. We also show that in these devices, which have relative transparent contacts with resistances in the range of 10 − 100 kΩ, the magnitude of the oscillating V nl greatly exceeds any nonlocal spin signal.Our devices consist of single-wall CNTs grown by chemical vapor deposition (CVD) and contacted with four probes as shown in Fig 1a. Two middle electrodes are ferromagnetic (F) made of PdNi(20nm)/ Co(25nm)/ Pd(10nm) tri-layer, whereas the two outer probes are normal (N) Pd(40nm) electrodes. A PdNi alloy with 30% Pd is used, because it makes stable contacts to the CNT [1], whi...

show abstract

Four-probe measurements of carbon nanotubes with narrow metal contacts

Cited by 23 publications

References 15 publications

Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at liquid helium temperatures

Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at liquid helium temperatures

Conductivity of multiwall carbon nanotubes: Role of multiple shells and defects

Large oscillating nonlocal voltage in multiterminal single-wall carbon nanotube devices

Contact Info

Product

Resources

About