Tuesday, April 12, 2011
Jenny och Sanna
Systrar Sanna och Jenny Kallur är tillbaka. Båda två har återhämtat sig efter diverse skador och räknar med att tävla till sommaren. Hör de berätta i TV4-as Nyhetsmorgon Söndag.
Thursday, March 31, 2011
Graphene with a twist
Credit: A. Luican et al., Phys. Rev. Lett. (2011)
Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers
A. Luican, Guohong Li, A. Reina, J. Kong, R. R. Nair, K. S. Novoselov, A. K. Geim, and E. Y. Andrei
Phys. Rev. Lett. 106, 126802 (Published March 21, 2011)
Graphene
Stacks of graphene are expected to possess drastically different electronic properties compared to their single-layer components, as a result of interlayer coupling. Theory dictates that graphene’s massless low-energy excitations should disappear, even for the simple bilayer structure. However, experiments have shown that, paradoxically, the electronic properties of single layers somehow survive in layered structures. Theorists have suggested that a relative rotation of one layer with respect to the one below it—a “twist” in the stacking—might be the resolution of the paradox.
Now, in a paper appearing in Physical Review Letters, Adina Luican and collaborators from Rutgers University and the Massachusetts Institute of Technology, both in the US, and the University of Manchester, UK, provide experimental proof of the influence of twisting on the band structure of bilayer graphene. Using scanning tunneling microscopy and spectroscopy, the researchers find that for twist angles above 20°, the electronic properties of the twisted layers are practically indistinguishable from those of single-layer graphene. Based on their measurements, Luican et al. conclude that at small angles, the massless Dirac fermion picture of graphene breaks down and the electronic spectrum is dominated by a saddle point feature, while at large rotation angles, the intersection point in the spectrum shifts to irrelevant high energies and the familiar Dirac energy dispersion is recovered. – Alexios Klironomos
Single-Layer Behavior and Its Breakdown in Twisted Graphene Layers
A. Luican, Guohong Li, A. Reina, J. Kong, R. R. Nair, K. S. Novoselov, A. K. Geim, and E. Y. Andrei
Phys. Rev. Lett. 106, 126802 (Published March 21, 2011)
Graphene
Stacks of graphene are expected to possess drastically different electronic properties compared to their single-layer components, as a result of interlayer coupling. Theory dictates that graphene’s massless low-energy excitations should disappear, even for the simple bilayer structure. However, experiments have shown that, paradoxically, the electronic properties of single layers somehow survive in layered structures. Theorists have suggested that a relative rotation of one layer with respect to the one below it—a “twist” in the stacking—might be the resolution of the paradox.
Now, in a paper appearing in Physical Review Letters, Adina Luican and collaborators from Rutgers University and the Massachusetts Institute of Technology, both in the US, and the University of Manchester, UK, provide experimental proof of the influence of twisting on the band structure of bilayer graphene. Using scanning tunneling microscopy and spectroscopy, the researchers find that for twist angles above 20°, the electronic properties of the twisted layers are practically indistinguishable from those of single-layer graphene. Based on their measurements, Luican et al. conclude that at small angles, the massless Dirac fermion picture of graphene breaks down and the electronic spectrum is dominated by a saddle point feature, while at large rotation angles, the intersection point in the spectrum shifts to irrelevant high energies and the familiar Dirac energy dispersion is recovered. – Alexios Klironomos
Wednesday, March 30, 2011
Monday, February 14, 2011
My definition of Skår
Some words are not in my Swedish dictionary. Apparently, This is because they are considered to be Norwegian. So, I make up my own definition.
Skår is a noun meaning a score (as in carpentry) in the sense of a cutting. It is a Norwegian word used in Swedish. It is a suburb of GBG located in the borough, i.e., stadsdelsnämndsområden, of Örgryte. It is directly east of Liseberg. Skår är en stadsdel i Göteborg.
Google directions from Skår to Liseberg. 2.0 km
1. Head south on Skårsgatan toward Förtroligheten
600 m
2. At the traffic circle, take the 3rd exit onto Sankt Sigfridsgatan
950 m
3. Turn right at Mölndalsvägen
1.0 km
4. Continue onto Södra Vägen
600 m
5. At Korsvägen, take the 2nd exit onto Örgrytevägen
Destination will be on the right
190 m
Liseberg
Örgrytevägen 5
412 51 Gothenburg urban area, Sweden
Skår is a noun meaning a score (as in carpentry) in the sense of a cutting. It is a Norwegian word used in Swedish. It is a suburb of GBG located in the borough, i.e., stadsdelsnämndsområden, of Örgryte. It is directly east of Liseberg. Skår är en stadsdel i Göteborg.
Google directions from Skår to Liseberg. 2.0 km
1. Head south on Skårsgatan toward Förtroligheten
600 m
2. At the traffic circle, take the 3rd exit onto Sankt Sigfridsgatan
950 m
3. Turn right at Mölndalsvägen
1.0 km
4. Continue onto Södra Vägen
600 m
5. At Korsvägen, take the 2nd exit onto Örgrytevägen
Destination will be on the right
190 m
Liseberg
Örgrytevägen 5
412 51 Gothenburg urban area, Sweden
Sunday, February 13, 2011
Thursday, January 27, 2011
Monday, January 24, 2011
Friday, January 14, 2011
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