The latest achievements of solid state physics

Prof. V.F.Gantmakher

Annotation

The seminar is intended for 10-th term students who have already accomplished their academic fiztech program and are working in laboratories elaborating their MPhil’s. Main purpose of the seminar is to prevent their complete self isolating inside the specific problem of the master work, to give them feeling of close connection with the solid physics as a whole, to demonstrate diversity of experimental approaches and ways of reasoning. All this – by analyzing recently published papers or those which still exist in electronic form only.

Seminar functions as follows. Seminar manager selects works/papers for discussion, distributes them among the participants (usually one per person) in advance and announces discussions schedule. He also checks the preparation progress of the coming talk several days before the due date, and usually gives a short introduction at the seminar. It is desirable for seminar participants to get involved into active discussion.

For 2012-13 school year, the following papers are selected for discussion ( the list may be changed or extended):

1. Yu Lin, Li Zhang, et al., Amorphous Diamond: A High-Pressure Superhard Carbon Allotrope, PRL 107, 175504 (2011)
   By compressing glassy carbon above 40 GPa, a new carbon allotrope with a fully sp3-bonded amorphous structure and diamondlike strength was prepared. However, the transition was reversible upon releasing pressure.
2. Y. Bekenstein, K. Vinokurov, et al., Periodic negative differential conductance in a single metallic nanocage, cond.-mat. 1209.2241, Phys. Rev. B. 86, 085431, 2012 A bipolar multiple periodic negative differential conductance (NDC) effect on a single cage-shaped Ru nanoparticle was measured using scanning tunneling spectroscopy. Possible mechanisms of NDC are discussed
3. N. Deng, J.D. Watson, et al., Contrasting Energy Scales of the Reentrant Integer Quantum Hall States, cond.-mat. 1209.2395
   Drastically different onset temperatures of the reentrant integer quantum Hall states in the second and third Landau level were detected.
4. A. Richardella, A. Yazdani, et al., Visualizing Critical Correlations Near the Metal-Insulator Transition in Ga1-xMnxAs. SCIENCE 327, 665 (2010)
   Metal-Insulator Transition in Ga1-xMnxAs. SCIENCE 327, 665 (2010) Electronic states in disordered conductors on the verge of localization are predicted to exhibit critical spatial characteristics indicative of the proximity to a metal-insulator phase transition. By using scanning tunneling microscopy, electronic states in Ga1-xMnxAs samples were visualized close to this transition.
5. D. Kim, S. Cho, et al., Surface conduction of topological Dirac electrons in bulk insulating Bi2Se3, NATURE PHYSICS, 8, 459 (2012).
   Despite their name, the bulk electrical conductivity of most topological insulators is relatively high, masking many of the important characteristics of its protected, surface conducting states. Counter-doping reduces the bulk conductivity of Bi2Se3 significantly, allowing these surface states and their properties to be clearly identified.
6. C. Kallin, Chiral P-Wave Order in Sr2RuO4, arXiv: 1210.2992
   Review a broad range of experiments on Sr2RuO4 that are sensitive to p-wave pairing, triplet superconductivity and time-reversal symmetry breaking is presented.
7. J. Hicks,1 A. Tejeda, et al., A wide band gap metal-semiconductor-metal nanostructure made entirely from graphene, arXiv: 1210.3532
   A unique one-dimensional metallic-semiconducting-metallic junction made entirely from grapheme is produced by taking advantage of the inherent, atomically ordered, substrate-graphene interaction.