Absence of Luttinger s Theorem Kiaran dave Charlie Kane
n = µ N(ω)dω µ IR UV
n = µ N(ω)dω µ IR UV can n be deduced entirely from the IR(lowenergy) scale?
Luttinger s theorem n =2 k Θ(G(k,ω = 0))
Luttinger s theorem n =2 k Θ(G(k,ω = 0))
Luttinger s theorem G(E) = 1 E ε p n =2 k Θ(G(k,ω = 0)) E>ε p ε p E E<ε p counting poles (qp)
Luttinger s theorem G(E) = 1 E ε p n =2 k Θ(G(k,ω = 0)) zero-crossing E>ε p ε p E ε p E E<ε p counting poles (qp)
Luttinger s theorem G(E) = 1 E ε p n =2 k Θ(G(k,ω = 0)) zero-crossing DetG(ω =0,p)=0 ε p E>ε p E ε p E E<ε p counting poles (qp)
singularities of ln G n = 2i (2π) d+1 d d p 0 dξ ln GR (ξ,p) G R (ξ,p) poles+zeros (all sign changes)
singularities of ln G n = 2i (2π) d+1 d d p 0 dξ ln GR (ξ,p) G R (ξ,p) n =2 k Θ(G(k,ω = 0)) poles+zeros (all sign changes)
simple problem: n=1 SU(2) U
simple problem: n=1 SU(2) µ U
simple problem: n=1 SU(2) µ U U 2
simple problem: n=1 SU(2) U 2 µ U U 2
simple problem: n=1 SU(2) U 2 µ U U 2 G = 1 ω + U/2 + 1 ω U/2
simple problem: n=1 SU(2) U 2 µ U U 2 G = 1 ω + U/2 + 1 ω U/2 =0 if ω =0
simple problem: n=1 SU(2) U 2 µ U U 2 G = 1 ω + U/2 + 1 ω U/2 n =2θ(0) = 1 =0 if ω =0
Is this famous theorem from 1960 correct?
SU(N) H = U 2 (n 1 + n N ) 2 2E 25 N =5 16 4 9 1
compute Green function exactly (Lehman formula) G αβ (ω) = 1 Z ab exp βk a Q ab αβ Q ab αβ = a c α bb c β a ω K b + K a + a c β bb c α a ω K a + K b do sum explicitly
G αβ (ω = 0) = δ αβ K(n + 1) K(n) 2n N N
G αβ (ω = 0) = δ αβ K(n + 1) K(n) 2n N N } > 0
Luttinger s theorem n = NΘ(2n N)
Luttinger s theorem n = NΘ(2n N) { 0, 1, 1/2
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2 2=3
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2 2=3
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2 even 2=3
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2 even 2=3 odd
Luttinger s theorem n = NΘ(2n N) n =2 N =3 { 0, 1, 1/2 even 2=3 odd no solution
does the degeneracy matter? e t t t t t t t t t =0 +
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω H c a ρ(0 + )
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω H c a ρ(0 + )
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω HU c a ρ(0 + )
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω HU c a ρ(0 + ) G ab (ω) = ωδ ab Uρ ab ω(ω U)
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω HU c a ρ(0 + ) ρ ab =Tr c ac b ρ(0 + ) = u 0 c ac b u 0 G ab (ω) = ωδ ab Uρ ab ω(ω U)
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω HU c a ρ(0 + ) ρ ab =Tr c ac b ρ(0 + ) = u 0 c ac b u 0 G ab (ω) = ωδ ab Uρ ab ω(ω U) 1/N diag(1, 1, 1, ) mixed state
G ab (ω) =Tr c a 1 ω H c 1 b + c b ω ω HU c a ρ(0 + ) ρ ab =Tr c ac b ρ(0 + ) = u 0 c ac b u 0 G ab (ω) = ωδ ab Uρ ab ω(ω U) 1/N diag(1, 1, 1, ) mixed state as long as SU(N) symmetry is intact zeros in the wrong place
Problem
Problem G=0
Problem G=0 G = 1 E ε p =0??
Problem G=0 G = 1 E ε p =0?? G = 1 E ε p Σ
Problem G=0 G = 1 E ε p =0?? G = 1 E ε p Σ
Problem G=0 G = 1 E ε p =0?? G = 1 E ε p Σ G=0
if Σ is infinite
if Σ is infinite lifetime of a particle vanishes
if Σ is infinite lifetime of a particle Σ < p vanishes
if Σ is infinite lifetime of a particle Σ < p vanishes no particle
what went wrong?
what went wrong? δi[g] = dωσδg
what went wrong? δi[g] = dωσδg if Σ
what went wrong? δi[g] = dωσδg if Σ integral does not exist
what went wrong? δi[g] = dωσδg if Σ integral does not exist No Luttinger theorem!
Luttinger s theorem
are zeros important?
Fermi Arcs
Fermi Arcs
Fermi Arcs Re G Changes Sign across An arc
Fermi Arcs Re G Changes Sign across An arc Must cross A zero line (DetG=0)!!! Fermi arcs necessarily imply zeros exist.
what is seen experimentally? Fermi arcs: no double crossings (PDJ,JCC,ZXS)
what is seen experimentally? Fermi arcs: no double crossings (PDJ,JCC,ZXS) seen infinities not seen zeros E F k
experimental data (LSCO) `Luttinger count k F 1 x FS zeros do not affect the particle density
experimental data (LSCO) `Luttinger count k F 1 x FS Bi2212 zeros do not affect the particle density
experimental data (LSCO) `Luttinger count k F 1 x FS Bi2212 zeros do not affect the particle density each hole = a single k-state
how to count particles? 7 8 5 6 3 2 1 4
how to count particles? 7 8 5 6 3 2 1 4 some charged stuff has no particle interpretation