Unparticles and Emergent Mottness Thanks to: NSF, EFRC (DOE) Kiaran dave Charlie Kane Brandon Langley J. A. Hutasoit
Correlated Electron Matter
Correlated Electron Matter What is carrying the current?
fractional quantum Hall effect current-carrying excitations e = e q (q odd)
fractional quantum Hall effect current-carrying excitations e = e q (q odd)
fractional quantum Hall effect current-carrying excitations
fractional quantum Hall effect current-carrying excitations e =?
How Does Fermi Liquid Theory Breakdown? TRSB ρ at? LaSrCuO
How Does Fermi Liquid Theory Breakdown? TRSB ρ at? LaSrCuO
can the charge density be given a particle interpretation?
can the charge density be given a particle interpretation? does charge density= total number of electrons?
if not?
if not? charge stuff= particles + other stuff
if not? charge stuff= particles + other stuff unparticles!
counting particles
counting particles 1
counting particles 2 1
counting particles 2 3 1
counting particles 7 8 5 6 3 2 1 4
counting particles 7 8 5 6 3 2 1 4 is there a more efficient way?
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
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)
what are zeros?
what are zeros? Im G=0 µ =0
what are zeros? Im G=0 µ =0 ReG(0,p)= ( ) dω ω Kramers -Kronig
what are zeros? Im G=0 µ =0 ReG(0,p)= ( ) dω ω Kramers -Kronig = below gap+above gap
what are zeros? Im G=0 µ =0 ReG(0,p)= ( ) dω ω Kramers -Kronig = below gap+above gap = 0
what are zeros? Im G=0 µ =0 ReG(0,p)= ( ) dω ω Kramers -Kronig = below gap+above gap = 0 DetG(k,ω = 0) =0 (single band)
what are zeros? Im G=0 µ =0 ReG(0,p)= ( ) dω ω Kramers -Kronig = below gap+above gap = 0 DetG(k,ω = 0) =0 (single band) strongly correlated gapped systems
NiO insulates d 8? Mott mechanism (not Slater) t
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t U t
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t U t µ =0
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t U t µ =0 no change in size of Brillouin zone
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t U t µ =0 no change in size of Brillouin zone DetReG(0,p)=0
NiO insulates d 8? perhaps this costs energy Mott mechanism (not Slater) t U t µ =0 no change in size of Brillouin zone DetReG(0,p)=0 =Mottness
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
Fermi Liquids Mott Insulators Luttinger s theorem
Is this famous theorem from 1960 correct?
A model with zeros but Luttinger fails
A model with zeros but Luttinger fails e t t t t t t t t
A model with zeros but Luttinger fails e t t t t t t t t
A model with zeros but Luttinger fails e t t t t t t t t no hopping=> no propagation (zeros)
A model with zeros but Luttinger fails N flavors e t t t t t of e- t t t no hopping=> no propagation (zeros)
SU(N) H = U 2 (n 1 + n N ) 2 2E 25 N =5 16 4 9 1
SU(N) for N=3: no particle-hole symmetry
SU(N) for N=3: no particle-hole symmetry lim µ(t ) T 0
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) 0 2n N N
G αβ (ω = 0) = δ αβ K(n + }> 1) K(n) 0 2n N N
< 0 G αβ (ω = 0) = δ αβ K(n + }> 1) K(n) 0 2n N N
< 0 > 0 G αβ (ω = 0) = δ αβ K(n + }> 1) K(n) 0 2n N N
a zero must exist < 0 > 0 G αβ (ω = 0) = δ αβ K(n + }> 1) K(n) 0 2n N N
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
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 limiting procedure: lim lim t 0 ω 0
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 limiting procedure: lim lim t 0 ω 0 limits do not commute
Problem DetG =0 G = 1 E ε p =0??
Problem DetG =0 G = 1 E ε p =0?? G = 1 E ε p Σ
Problem DetG =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!
zeros and particles are incompatible
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 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
where do these zeros come from?
counting electron states need to know: N (number of sites)
counting electron states x = n h /N need to know: N (number of sites)
counting electron states x = n h /N removal states 1 x need to know: N (number of sites)
counting electron states x = n h /N removal states 1 x addition states 1+x need to know: N (number of sites)
counting electron states 2x x = n h /N removal states 1 x addition states 1+x need to know: N (number of sites)
counting electron states 2x x = n h /N removal states 1 x addition states 1+x low-energy electron states 1 x +2x =1+x need to know: N (number of sites)
counting electron states 2x x = n h /N removal states 1 x addition states 1+x low-energy electron states 1 x +2x =1+x high energy 1 x need to know: N (number of sites)
spectral function (dynamics)
spectral function (dynamics)
spectral function (dynamics) density of states 1+x + α>1+x U t Harris and Lange (1967)
spectral function (dynamics) density of states 1+x + α>1+x α t/u U t 1 x α Harris and Lange (1967)
spectral function (dynamics) density of states 1+x + α>1+x α t/u U t 1 x α Harris and Lange (1967) not exhausted by counting electrons alone
how to count particles? 7 8 5 6 3 2 1 4 some charged stuff has no particle interpretation
what is the extra stuff?
scale invariance
new fixed point (scale invariance)?
new fixed point (scale invariance)
new fixed point (scale invariance) unparticles (IR) (H. Georgi)
what is scale invariance? invariance on all length scales
spectral function from scale invariance A(Λω, Λ α k k)=λ α A A(ω, k)
spectral function from scale invariance A(Λω, Λ α k k)=λ α A A(ω, k) k A(ω, k)=ω α A f ω α k
what s the underlying theory?
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2 x x/λ φ(x) φ(x)
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2 x x/λ φ(x) φ(x) m 2 φ 2
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2 Λ 2 1 2 µ φ µ φ x x/λ φ(x) φ(x) m 2 φ 2
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2 Λ 2 1 2 µ φ µ φ x x/λ φ(x) φ(x) m 2 φ 2
massive free theory mass L = 1 2 µ φ µ φ + m 2 φ 2 Λ 2 1 2 µ φ µ φ x x/λ φ(x) φ(x) m 2 φ 2 no scale invariance
mass sets a scale
unparticles from a massive theory?
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m)
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2 theory with all possible mass!
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2 theory with all possible mass! φ φ(x, m 2 /Λ 2 ) x x/λ m 2 /Λ 2 m 2
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2 theory with all possible mass! φ φ(x, m 2 /Λ 2 ) x x/λ m 2 /Λ 2 m 2 L Λ 4 L scale invariance is restored!!
L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2 theory with all possible mass! φ φ(x, m 2 /Λ 2 ) x x/λ m 2 /Λ 2 m 2 L Λ 4 L scale invariance is restored!! not particles
unparticles L = µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 dm 2 theory with all possible mass! φ φ(x, m 2 /Λ 2 ) x x/λ m 2 /Λ 2 m 2 L Λ 4 L scale invariance is restored!! not particles
propagator 0 dm 2 m 2γ i p 2 m 2 + i 1 p 2 γ
propagator 0 dm 2 m 2γ i p 2 m 2 + i 1 p 2 γ d U 2
n massless particles G (E ε p ) n 2
n massless particles G (E ε p ) n 2 G (E ε p ) d U 2
n massless particles G (E ε p ) n 2 G (E ε p ) d U 2 unparticles=fractional number of massless particles
n massless particles G (E ε p ) n 2 G (E ε p ) d U 2 unparticles=fractional number of massless particles d U < 2 almost Luttinger liquid no pole at p_f
n massless particles G (E ε p ) n 2 G (E ε p ) d U 2 unparticles=fractional number of massless particles d U > 2 d U < 2 zeros almost Luttinger liquid no pole at p_f
n massless particles G (E ε p ) n 2 G (E ε p ) d U 2 unparticles=fractional number of massless particles d U > 2 d U < 2 zeros no simple sign change almost Luttinger liquid no pole at p_f
no particle interpretation mass-distribution φ U = B(m 2 )φ(m 2 )dm 2 unparticle field (non-canonical) particle field
d U?
what really is the summation over mass?
what really is the summation over mass? mass=energy
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2 m = z 1
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2 m = z 1 L = 0 dz 2R2 z 5+2δ 1 2 z 2 R 2 ηµν ( µ φ)( ν φ)+ φ2 2R 2
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2 m = z 1 L = 0 dz 2R2 z 5+2δ 1 2 z 2 R 2 ηµν ( µ φ)( ν φ)+ φ2 2R 2 can be absorbed with
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2 m = z 1 L = 0 dz 2R2 z 5+2δ 1 2 z 2 R 2 ηµν ( µ φ)( ν φ)+ φ2 2R 2 can be absorbed with ds 2 = R2 z 2 ηµν dx µ dx ν + dz 2
L = summation over mass? µ φ(x, m) µ φ(x, m)+m 2 φ 2 (x, m) 0 m 2δ dm 2 m = z 1 L = 0 dz 2R2 z 5+2δ 1 2 z 2 R 2 ηµν ( µ φ)( ν φ)+ φ2 2R 2 anti de Sitter can be absorbed with space! ds 2 = R2 z 2 ηµν dx µ dx ν + dz 2
generating functional for unparticles action on AdS 5+2δ a Φ a Φ+ Φ2 S = 1 2 d 4+2δ xdz g R 2
generating functional for unparticles action on AdS 5+2δ a Φ a Φ+ Φ2 S = 1 2 d 4+2δ xdz g R 2 ds 2 = L2 z 2 ηµν dx µ dx ν + dz 2 g =(R/z) 5+2δ
generating functional for unparticles action on AdS 5+2δ a Φ a Φ+ Φ2 S = 1 2 d 4+2δ xdz g R 2 ds 2 = L2 z 2 ηµν dx µ dx ν + dz 2 g =(R/z) 5+2δ unparticle lives in d =4+2δ δ 0
gauge-gravity duality (Maldacena, 1997) UV IR gravity QF T
gauge-gravity duality (Maldacena, 1997) UV IR gravity IR?? QF T
gauge-gravity duality (Maldacena, 1997) UV IR gravity IR?? QF T dg(e) dlne = β(g(e)) locality in energy
gauge-gravity duality (Maldacena, 1997) implement E-scaling with an extra dimension UV IR gravity IR?? QF T dg(e) dlne = β(g(e)) locality in energy
Claim: Z QFT = e Son shell ADS (φ(φ ADS=JO ))
Claim: Z QFT = e Son shell ADS (φ(φ ADS=JO )) S = 1 2 d d xg zz g Φ(z,x) z Φ(z,x) z=
Claim: Z QFT = e Son shell ADS (φ(φ ADS=JO )) S = 1 2 d d xg zz g Φ(z,x) z Φ(z,x) z= Φ U (x)φ U (x ) = 1 x x 2d U
Claim: Z QFT = e Son shell ADS (φ(φ ADS=JO )) S = 1 2 d d xg zz g Φ(z,x) z Φ(z,x) z= Φ U (x)φ U (x ) = 1 x x 2d U d U = d 2 + d2 +4 2 > d 2
Claim: Z QFT = e Son shell ADS (φ(φ ADS=JO )) S = 1 2 d d xg zz g Φ(z,x) z Φ(z,x) z= Φ U (x)φ U (x ) = 1 x x 2d U d U = d 2 + d2 +4 2 > d 2 scaling dimension is fixed
G U (p) p 2(d U d/2) d U = d 2 + d2 +4 2 > d 2 G U (0) = 0
unparticle (AdS) propagator has zeros! G U (p) p 2(d U d/2) d U = d 2 + d2 +4 2 > d 2 G U (0) = 0
interchanging unparticles fractional (d_u) number of massless particles
interchanging unparticles fractional (d_u) number of massless particles
interchanging unparticles fractional (d_u) number of massless particles
interchanging unparticles fractional (d_u) number of massless particles
interchanging unparticles fractional (d_u) number of massless particles e iπd U = 1, 0
interchanging unparticles fractional (d_u) number of massless particles e iπd U = 1, 0 fractional statistics in d=2+1
d U = d 2 + d2 +4 2 > d 2 e iπd U = e iπd U time-reversal symmetry breaking from unparticle (zeros=fermi arcs) matter
d ln g d ln β = 4d U d>0 fermions T c unparticles with unparticle propagator BCS g tendency towards pairing (any instability which establishes a gap)
TRSB
TRSB
TRSB unparticles
TRSB unparticles particles
breaking of scale invariance TRSB unparticles particles
emergent gravity High T_c unparticles variable mass
emergent gravity High T_c unparticles variable mass fractional statistics in d=2+1