Room-temperature-operating carbon nanotube single-hole transistors with significantly small gate and tunnel capacitances

Ohno, Yasuhide; Asai, Yoshihiro; Maehashi, Kenzo; Inoue, Kōichi; Matsumoto, Kazuhiko

doi:10.1063/1.3078234

Cited by 34 publications

(24 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, in semiconductor quantum dots 5,39,70-75 Γ 0.5 meV and U hardly ever exceeds a few meV. In carbon-nanotube quantum dots 62,66,76-78 Γ and U can vary in a significantly broader range with U even reaching tens of meV 79,80 (typically…”

Section: E Estimation Of Experimentally Achievable Spintronic Anisotmentioning

confidence: 99%

Spintronic magnetic anisotropy

2013

View full text Add to dashboard Cite

An attractive feature of magnetic adatoms and molecules for nanoscale applications is their superparamagnetism, the preferred alignment of their spin along an easy axis preventing undesired spin reversal. The underlying magnetic anisotropy barrier -a quadrupolar energy splitting -is internally generated by spin-orbit interaction and can nowadays be probed by electronic transport. Here we predict that in a much broader class of quantum-dot systems with spin larger than one-half, superparamagnetism may arise without spin-orbit interaction: by attaching ferromagnets a spintronic exchange field of quadrupolar nature is generated locally. It can be observed in conductance measurements and surprisingly leads to enhanced spin filtering even in a state with zero average spin. Analogously to the spintronic dipolar exchange field, responsible for a local spin torque, the effect is susceptible to electric control and increases with tunnel coupling as well as with spin polarization.The growing interest in nanomagnets, e.g., magnetic adatoms 1 and single-molecule magnets 2 is fueled by prospects of their application in novel spintronic devices whose functionality derives from their unique magnetic features 3 . A key property of such systems is their strong magnetic anisotropy leading to magnetic bistability, required for building blocks for nanoscale memory cells 4,5 and non-trivial quantum dynamics, useful for quantum information processing 6,7 . In either case, operational stability of such devices hinges heavily on the height of the energy barrier opposing the spin reversal. Though recently progress in the control over the magnetic anisotropy by synthesis 8 , mechanical straining 9 , atomic manipulation 10 or electrical gating 11 has been made, achieving of a high spin-reversal barrier still remains a challenge. Incorporating a nanomagnet into an electronic circuit may significantly alter its magnetic properties [12][13][14] , but may also be advantageous. One possible, spintronic route for manipulation of nanomagnets entails ferromagnetic electrodes and uses the spin torque due to spin-polarized scattering 15 or Coulomb interaction 16 , magnetic analogs of the proximity effect in superconducting junctions. In this article, we present another route that combines spintronics with molecular magnetism: high-spin quantum dots can acquire a significant magnetic anisotropy that is purely of spintronic origin, instead of deriving from the spin-orbit interaction, as the tunneling to ferromagnets induces a local, quadrupolar exchange field. Besides providing an alternative approach to electrical manipulation and engineering of superparamagnetic nanomagnets, this new quantity is of key importance for the analysis of experiments that probe atoms or molecules using highly spin-polarized electrodes. DIPOLAR VS. QUADRUPOLAR EXCHANGE FIELDThe origin of superparamagnetism, usually dominating the magnetic behaviour of a nanomagnet, is a magnetic anisotropy energy barrier. For instance, an adatom with a spin-degenerate ground multiplet (q...

show abstract

Section: E Estimation Of Experimentally Achievable Spintronic Anisotmentioning

confidence: 99%

Spintronic magnetic anisotropy

2013

View full text Add to dashboard Cite

show abstract

“…Several technologies can be utilized in these applications, such as high-sensitive gas sensors [3], label-free detection for bio molecules [4,5], and n-type field effect transistor (FET) fabrication [6,7]. The room temperature operation of single electron transistors, which can usually work only at low temperature, can be archived through the use of nanotechnology [8,9].…”

Section: Introductionmentioning

confidence: 99%

Cobalt Nano Particle Size Dependence of Noise Modulations in Relation to Nonlinearity

Kawahara

Yamaguchi

Maehashi

et al. 2010

e-J. Surf. Sci. Nanotechnol.

Self Cite

View full text Add to dashboard Cite

Carbon nanotubes (CNTs) are low-dimensional materials, and their surface therefore affects several properties of CNTs. For example, CNT field effect transistors (CNTFETs) are well known as noisy devices caused by the adhesion of molecules on the surface. However, nonlinear systems sometimes have advantages in working with noise. Therefore, we combined the noise CNTFET and another transistor of CNT for a trial nonlinear system. The sine wave amplification in the transistor with noise was then measured. In this system, the control of noise is required for operation of the device and this might be common for nano-sized devices. We can control the noise properties of CNTFET through the control of the Co nano particles catalyst. Depending on fabrication conditions, the noise of a CNTFET has different noise intensity and gate voltage (Vg) dependence with 1/f type noise. Noise in CNTFETs grown on small Co particles can be controlled within the small |Vg|, and the control range for noise is wide. We studied the modification of nonlinearity using our trial nonlinear system. It was governed by the ratio of the signals and the noise, and shows the robustness of modification.

show abstract

“…[1][2][3][4][5][6] In particular, carbon nanotube FETs (CNTFETs) are one of the promising candidates for application as highly integrated CNT-based circuits and highly sensitive label-free sensors, 7-14 because they have excellent transport properties with high mobility. Thus, CNTFETs with high performance are necessary to realize such devices.…”

Section: Introductionmentioning

confidence: 99%

Improvement in Performance of Carbon Nanotube Field-Effect Transistors on Patterned SiO2/Si Substrates

Maehashi

Iwasaki

Ohno

et al. 2009

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

Horizontally aligned single-walled carbon nanotubes (SWNTs) were fabricated on patterned SiO 2 /Si substrates with groove-and-terrace structures, which were obtained using electron-beam lithography and reactive ion etching. Scanning electron microscopy observation revealed that SWNTs were aligned in the direction parallel to the groove-and-terrace structures and were preferentially grown along the edges of terraces. Using aligned SWNTs as multichannels, carbon nanotube field-effect transistors (CNTFETs) were fabricated on the patterned SiO 2 /Si substrates. This method will be promising to control the direction of SWNTs on SiO 2 /Si substrates for fabrication of highperformance CNTFETs with high current outputs.

show abstract

Room-temperature-operating carbon nanotube single-hole transistors with significantly small gate and tunnel capacitances

Cited by 34 publications

References 22 publications

Spintronic magnetic anisotropy

Spintronic magnetic anisotropy

Cobalt Nano Particle Size Dependence of Noise Modulations in Relation to Nonlinearity

Improvement in Performance of Carbon Nanotube Field-Effect Transistors on Patterned SiO2/Si Substrates

Contact Info

Product

Resources

About