SLIDE 1
Na Ce1-xLaxRu2Si2
3He
1
a) β b) β c) β d) β
Reasonable expansion order Order controlled through interaction
Rubtsov et al. ’05 Gull et al., RMP 83, 349 (2011)
k / βh ˆ H1i ˆ H1[τk] ˆ H1[τl] ˆ H1[τm]
2
3 He Na Ce 1-x La x Ru 2 Si 2 1 Rubtsov et al. 05 Gull et al., RMP - - PowerPoint PPT Presentation
3 He Na Ce 1-x La x Ru 2 Si 2 1 Rubtsov et al. 05 Gull et al., RMP - - PowerPoint PPT Presentation
3 He Na Ce 1-x La x Ru 2 Si 2 1 Rubtsov et al. 05 Gull et al., RMP 83 , 349 (2011) b) H 1 [ k ] H 1 [ l ] H 1 [ m ] 0 a) c) 0 0 d) 0 Reasonable expansion order Order controlled through interaction
SLIDE 2
SLIDE 3
10
- 6
10
- 4
10
- 2
10 10
2
10
4
T/TK 0.5 1 1.5 2 2.5 S/ln(2) 4TKχimp TKγimp RW
3
SLIDE 4
10
−3 10 −2 10 −1
10 10
1
10
2
10
3
10
4
10
5
T/TK
0.0 0.2 0.4 0.6 0.8 1.0 1.2 R(T)/R(0), G(T)/G(0)
R(T) Kondo Model G(T) Kondo Model R(T) Anderson Model R(T)/R(0)=1−c(T/TK)
2
Hamann
3
SLIDE 5
10
- 6
10
- 4
10
- 2
10 10
2
10
4
T/TK 0.2 0.4 0.6 0.8 1 1.2 1.4
S/ln(2) TKχimp TKγimp RW/(8/3)
3
SLIDE 6
Γ X M R
- 10
- 5
5 10 0.05 0.1 0.15 ω/t Alok(ω)/t−1 R M X Γ R k
Lattice 1st Brillouin zone Lattice DOS ε εk EF
4
SLIDE 7
- 1
1 k/
- W/2
W/2 Ek
- Static Néel order:
Doubling of unit cell = reduction of BZ = backfolding of bands
- New BZ = old Fermi
surface
- Formation of bonding-/
antibonding bands
5
SLIDE 8
- 10
- 5
5 10 0.05 0.1 0.15 ω/t Alok(ω)/t−1 R M X Γ R k 0.1 0.2 0.3 0.4 Ak(ω)/t−1
Γ X M R
DOS ε εk EF
U = 2W/3
Fermi liquid
6
SLIDE 9
- 10
- 5
5 10 0.05 0.1 0.15 ω/t Alok(ω)/t−1 R M X Γ R k 0.1 0.2 0.3 0.4 Ak(ω)/t−1
Γ X M R
DOS ε εk EF
U = 0.87W
Insulator (no Fermi liquid)
6
SLIDE 10
Γ kF
- 1. BZ
k 1 n(k)
real particles quasi-particles
1 m∗
7
SLIDE 11
Magnetic properties at half filling:
5 10 15 20 U/t 0.2 0.4 0.6 0.8 T/t
Weiss Heisenberg SOPT Staudt DMFA DCA Kent, TP et al., ’05
- Calculate staggered
susceptibility
- Perform finite-size
scaling up to size 32 Result:
- Tc(DCA)<Tc(DMFT)
- Large U ➫ Heisenberg
model Interesting: Properties for T<TN? antiferromagnetic insulator DCA DMFT „Mott“ „Slater“
8