PH10

67 %
33 %
Information about PH10
Entertainment

Published on October 15, 2007

Author: Reva

Source: authorstream.com

High Tc Superconductors in Magnetic Fields:  High Tc Superconductors in Magnetic Fields T. P. Devereaux Kamerlingh Onnes, 1913 Nobel Prize for Discovery of Superconductivity in Mercury:  Kamerlingh Onnes, 1913 Nobel Prize for Discovery of Superconductivity in Mercury Theory of Superconductivity by Bardeen, Cooper, and Schrieffer Earns Nobel Prize in 1972:  Theory of Superconductivity by Bardeen, Cooper, and Schrieffer Earns Nobel Prize in 1972 Most successful many-body theory. Quantum Coherent State “paired” electrons condense into coherent state -> no resistance. perfect diamagnetism – electrons circulate to screen magnetic field (Meissner effect). High Tc Superconductors Discovered in 1986, Nobel Prize for Bednorz and Müller in 1987:  High Tc Superconductors Discovered in 1986, Nobel Prize for Bednorz and Müller in 1987 Critical Current On the Rise :  Critical Current On the Rise New Superconductor Developments:  New Superconductor Developments Fullerenes: Tc engineered to 117K. Iron becomes a superconductor under pressure. Plastic superconductor: polythiophene. DNA can be made superconducting. MgB2 changes our thinking (again). Large Scale Applications:  Large Scale Applications Top speed: 552 km/hr In-place in Detroit.* US Navy: 5,000 HP* *American Superconductor Corp. Small Scale Devices?:  Small Scale Devices? Transistors (RSFQ peta-flop supercomputer)? Filters? Nano-scale motors and devices? Superconducting DNA? Quantum computers!? OBSTACLES: cooling. architecture. ever-present magnetic fields destroy coherence. Small Devices? Magnetic Fields!:  Small Devices? Magnetic Fields! H. Safar et al (1993) <- Resistivity of Pure Copper Resistance reappears! Problem: Vortices!:  Problem: Vortices! Electrons swirl in magnetic field – increased kinetic energy kills superconductivity. SOLUTION: Magnetic field kills superconductivity in isolated places -> VORTICES (swirling “normal” electrons) Direct Vortex Imaging Using Scanning Tunneling Microscope:  Direct Vortex Imaging Using Scanning Tunneling Microscope Animation: Increasing Magnetic Field:  Animation: Increasing Magnetic Field Apply current: Lorentz force causes vortices to move -> Resistance! Solution: Defects to Pin Vortices:  Solution: Defects to Pin Vortices Krusin-Elbaum et al (1996). Critical current enhanced by orders of magnitude over “virgin” material. Splayed defects better than straight ones. Optimal splaying angle ~ 5 degrees. Animation: Pinning Moving Vortices:  Animation: Pinning Moving Vortices Problems to Overcome:  Problems to Overcome High TC Elastic string under tension F: Du2= kBTy(L-y)/FL ~ kBT/F String is floppier at higher T -> vortex “liquid” 2) Planar Structure “pancake” vortices in layers weakly coupled Decreased string tension -> vortex decoupling Molecular Dynamics Simulations:  Molecular Dynamics Simulations Widely used for a variety of problems: - protein folding, weather simulation, cosmology, chaos, avalanches, marine pollution, other non-equilibrium phenomena. Solves equations of motion for each “particle”. Large scale simulations on pcs and supercomputers (parallel). Molecular Dynamics Simulations for Vortices:  Molecular Dynamics Simulations for Vortices Vortices = elastic strings under tension. Vortices strongly interact (repel each other). Temperature treated as Langevin noise. Solve equations of motion for each vortex. Calculate current versus applied Lorentz force, find what type of disorder gives maximum critical current. Abrikosov Lattice Melting - > Vortex Liquid:  Abrikosov Lattice Melting - > Vortex Liquid At low T, lattice forms with “defects”. At higher T, lattice “melts”. Pinning:  Pinning At low T, a few pins can stop whole “lattice”. At larger T, pieces of “lattice” shear away. Pinning at low fields:  Pinning at low fields Columns of defects are effective at pinning vortices. But “channels” of vortex flow proliferate at larger fields. Depinning <-> vortex avalanche:  Depinning <-> vortex avalanche Splayed defects effective at cutting off channels of vortex flow:  Splayed defects effective at cutting off channels of vortex flow But too much splaying and vortices cannot accommodate to defects. Resistivity is smaller for splayed defects:  Resistivity is smaller for splayed defects Optimal angle for splaying:  Optimal angle for splaying Acknowledgement & Future Work:  Acknowledgement & Future Work All simulations performed by Dr. C. M. Palmer. Complex vortex dynamics. Future work to investigate Melting phenomena. Oscillatory motion of driven vortices. Onset of avalanches. Behavior as a qubit (quantum computing). Behavior of other dual systems (polymers, DNA,…).

Add a comment

Related presentations

Related pages

PH10: Patisserie von Pierre Hermé: Amazon.de: Pierre ...

Pierre Hermé - PH10: Patisserie von Pierre Hermé jetzt kaufen. 5 Kundrezensionen und 4.6 Sterne. Backen, Dessert, Süßspeise…
Read more

PH10 - Wikipedia, the free encyclopedia

pH10 is an electronica jungle/drum n bass group currently based in Denver, Colorado and has been churning out records since the late 90's. Most notably ...
Read more

PH10 - Matthaes Buchshop - Bücher direkt vom Matthaes ...

PH10, das Buch von Pierre Hermé, zeigt seine Kunst in einer Vollständigkeit, die es bisher nicht gab: Torten, Kuchen, Gebäck, Desserts, Eis, Macarons ...
Read more

PH10 PLUS motorised indexing heads - Renishaw: enhancing ...

Family of indexing heads (PH10M PLUS, PH10MQ PLUS and PH10T PLUS) with in-quill and probe mounting options.
Read more

PH10T PLUS motorischer Dreh-/Schwenkkopf - Mit Renishaw zu ...

Das Angebot umfasst drei PH10 PLUS Modelle, wobei jedes Model mit einer Auswahl an Tastern und Verlängerungen verwendet und in 720 Positionen ...
Read more

PH10 von Pierre Hermé - Buch - buecher.de

PH10, das Buch von Pierre Hermé, zeigt seine Kunst in einer Vollständigkeit, die es bisher nicht gab: Torten, Kuchen, Gebäck, Desserts, Eis, Macarons ...
Read more

PH10 - Pâtisserie von Pierre Hermé (deutsche Ausgabe ...

Patisserie von Pierre Herme PH10, das Buch von Pierre Hermé, zeigt seine Kunst in einer Vollständigkeit, die es bisher nicht gab: Torten, Kuchen, Gebäck ...
Read more

"PH10" – Bücher gebraucht und neu kaufen bei booklooker ...

Von 24 verschiedenen Händlern: Ph10 Antologia Pierre Herme 1995-2005 Las Creaciones De Una Deca Da (En Papel) Pierre Herme Montagud Editores Sa, 2008 ...
Read more

PH10 LED-Videowand

Modell: PH10 Silan-Chip Typ von Chip: Silan Bildfläche: 20m 2 Punktmatrix-Dichte: 10000/m 2 Abmessung von jedem Modul: 320mm*160mm Zahl von Modulen: 25 Stück
Read more

BBC Weather - PH10

BBC Weather in association with the Met Office. All times are GMT (Europe/London, GMT+0000) unless otherwise stated. Information given for most appropriate ...
Read more