scholarly journals Topological superconducting state and Majorana fermions in carbon nanotubes

2013 ◽  
Vol 88 (5) ◽  
Author(s):  
Jay D. Sau ◽  
Sumanta Tewari
Keyword(s):  
Carbon Nanotubes ◽  
Superconducting State ◽  
Majorana Fermions

scholarly journals Electric-field-induced Majorana Fermions in Armchair Carbon Nanotubes

2012 ◽  
Vol 108 (19) ◽  
Author(s):  
Jelena Klinovaja ◽  
Suhas Gangadharaiah ◽  
Daniel Loss
Keyword(s):  
Carbon Nanotubes ◽  
Electric Field ◽  
Majorana Fermions

Impossibility of superconducting state in multiwall carbon nanotubes and single crystal graphite

2003 ◽  
Vol 388-389 ◽  
pp. 622-623 ◽  
Author(s):  
Anatoly I Romanenko ◽  
Alexandr V Okotrub ◽  
Lubov G Bulusheva ◽  
Olga B Anikeeva ◽  
Nikolai F Yudanov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Single Crystal ◽  
Superconducting State ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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