Download presentation
Presentation is loading. Please wait.
Published byAmberlynn Nichols Modified over 8 years ago
1
From the Hubbard model to high temperature superconductivity HARVARD S. Sachdev Talk online: sachdev.physics.harvard.edu
2
Max Metlitski: Entanglement near strongly interacting quantum critical points in two and higher dimensions Yang Qi: Frustrated antiferromagnetism and spin liquids in organic insulators Posters HARVARD
3
The cuprate superconductors
4
Central ingredients in cuprate phase diagram: antiferromagnetism, superconductivity, and change in Fermi surface
5
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
6
Central ingredients in cuprate phase diagram: antiferromagnetism, superconductivity, and change in Fermi surface
7
N. E. Hussey, J. Phys: Condens. Matter 20, 123201 (2008) Crossovers in transport properties of hole-doped cuprates
8
Strange metal Crossovers in transport properties of hole-doped cuprates Pseudo- gap
9
Strange metal Crossovers in transport properties of hole-doped cuprates Pseudo- gap
10
How is antiferromagnetism lost with increasing doping ? How does the Fermi surface evolve with loss of antiferromagnetism ? Do antiferromagnetic fluctuations induce d-wave superconductivity ? How does attraction between antiferromagnetism and superconductivity turn into competition ? Is there a broken symmetry in the pseudo-gap regime ? What is the role of nematic/valence-bond-solid/stripe order ? What is the physics of the strange metal ? Questions
11
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
12
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
13
Ground state has long-range Néel order Square lattice antiferromagnet
14
J J/ Weaken some bonds to induce spin entanglement in a new quantum phase
15
Square lattice antiferromagnet J J/ Ground state is a “quantum paramagnet” with spins locked in valence bond singlets
16
Pressure in TlCuCl 3
17
Quantum critical point with non-local entanglement in spin wavefunction
24
Spin waves
38
Christian Ruegg, Bruce Normand, Masashige Matsumoto, Albert Furrer, Desmond McMorrow, Karl Kramer, Hans–Ulrich Gudel, Severian Gvasaliya, Hannu Mutka, and Martin Boehm, Phys. Rev. Lett. 100, 205701 (2008) TlCuCl 3 with varying pressure
39
Christian Ruegg, Bruce Normand, Masashige Matsumoto, Albert Furrer, Desmond McMorrow, Karl Kramer, Hans–Ulrich Gudel, Severian Gvasaliya, Hannu Mutka, and Martin Boehm, Phys. Rev. Lett. 100, 205701 (2008) TlCuCl 3 with varying pressure
40
Christian Ruegg, Bruce Normand, Masashige Matsumoto, Albert Furrer, Desmond McMorrow, Karl Kramer, Hans–Ulrich Gudel, Severian Gvasaliya, Hannu Mutka, and Martin Boehm, Phys. Rev. Lett. 100, 205701 (2008) TlCuCl 3 with varying pressure
41
Prediction of quantum field theory
42
Christian Ruegg, Bruce Normand, Masashige Matsumoto, Albert Furrer, Desmond McMorrow, Karl Kramer, Hans–Ulrich Gudel, Severian Gvasaliya, Hannu Mutka, and Martin Boehm, Phys. Rev. Lett. 100, 205701 (2008)
43
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
44
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
45
“Large” Fermi surfaces in cuprates Hole states occupied Electron states occupied
46
Spin density wave theory
48
S. Sachdev, A. V. Chubukov, and A. Sokol, Phys. Rev. B 51, 14874 (1995). A. V. Chubukov and D. K. Morr, Physics Reports 288, 355 (1997). D. Senechal and A.-M. S. Tremblay, Phys. Rev. Lett. 92, 126401 (2004) Hole pockets Electron pockets Hole-doped cuprates
49
Electron pockets Hole pockets Electron-doped cuprates S. Sachdev, A. V. Chubukov, and A. Sokol, Phys. Rev. B 51, 14874 (1995). A. V. Chubukov and D. K. Morr, Physics Reports 288, 355 (1997). D. Senechal and A.-M. S. Tremblay, Phys. Rev. Lett. 92, 126401 (2004)
50
N. P. Armitage et al., Phys. Rev. Lett. 88, 257001 (2002). Photoemission in NCCO
51
T. Helm, M. V. Kartsovnik, M. Bartkowiak, N. Bittner, M. Lambacher, A. Erb, J. Wosnitza, and R. Gross, Phys. Rev. Lett. 103, 157002 (2009).
52
Nature 450, 533 (2007) Quantum oscillations
53
Theory of quantum criticality in the cuprates
54
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
55
Antiferro- magnetism Fermi surface d-wave supercon- ductivity
56
Theory of quantum criticality in the cuprates
60
Criticality of the coupled dimer antiferromagnet at x=x s
61
Theory of quantum criticality in the cuprates Criticality of the topological change in Fermi surface at x=x m
62
Theory of quantum criticality in the cuprates
63
++ _ _ D. J. Scalapino, E. Loh, and J. E. Hirsch, Phys. Rev. B 34, 8190 (1986) K. Miyake, S. Schmitt-Rink, and C. M. Varma, Phys. Rev. B 34, 6554 (1986)
64
Theory of quantum criticality in the cuprates
66
How is antiferromagnetism lost with increasing doping ? How does the Fermi surface evolve with loss of antiferromagnetism ? Do antiferromagnetic fluctuations induce d-wave superconductivity ? How does attraction between antiferromagnetism and superconductivity turn into competition ? Is there a broken symmetry in the pseudo-gap regime ? What is the role of nematic/valence-bond-solid/stripe order ? What is the physics of the strange metal ? Questions
67
Max Metlitski: Entanglement near strongly interacting quantum critical points in two and higher dimensions Yang Qi: Frustrated antiferromagnetism and spin liquids in organic insulators Posters HARVARD
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.