X X 2 H = i + ( 1) ( x i x j ) i j 1 V ( x ) = ( x ) - - PowerPoint PPT Presentation

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X X 2 H = i + ( 1) ( x i x j ) i j 1 V ( x ) = ( x ) - - PowerPoint PPT Presentation

Non-linear dynamics of interacting electronic systems X X 2 H = i + V ( x i x j ) i i 6 = j X V k 0 V k 2 k F V k e ikx V ( x ) = k Lattinger liquid Model Hamiltonian: Elliptic Calogero-Sutherland model


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SLIDE 1

Non-linear dynamics of interacting electronic systems

H = − X

i

≥ − ∂2

i +

X

i6=j

V (xi − xj) ¥

Vk∼0 Vk∼2kF

Lattinger liquid

V (x) = X

k

Vkeikx

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SLIDE 2

Model Hamiltonian: Elliptic Calogero-Sutherland model

V (x) = ℘(x) → 1 x2 , 1 sinh2 x,

1 sin2 x, ∇δ(x)

Interpolates between Lattinger liquid and Calogero model - quantum wires, edge states of FQHE The last and the major unsolved integrable model

H = X

i

≥ − ∂2

i + λ(λ − 1)

X

j

℘(xi − xj) ¥

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SLIDE 3

˙ ϕ + (∂xϕ)2 = 0

Free fermions:

ρ(x) = −∇xϕ = ρ0 + X

k

akeikx [ak, ak0] = kδk+k0, ρk = ρ†

−k

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SLIDE 4

˙ ϕ = 1 2(∂xϕ)2 + ∂2

x ˜

ϕ

˜ ϕ = 1 πL Z cot x − x0 L ϕ(x0)dx0

℘(x + iL) = ℘(x)

chiral sector

H = X

i

≥ − ∂2

i + λ(λ − 1)

X

j

℘(xi − xj) ¥

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SLIDE 5

Chiral sector - long-time asymptotes of non-linear waves

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SLIDE 6

˜ ϕ = 1 πL Z cot x − x0 L ϕ(x0)dx0

L → 0 : ˙ ϕ = 1 2(∂xϕ)2 + ∂3

ILW-equation KdV-equation

L → ∞ : ˙ ϕ = 1 2(∂xϕ)2 + ∂2

x

Z ϕ(x0) x − x0 dx0

Benjamin-Ono equation

˙ ϕ = 1 2(∂xϕ)2 + (λ − 1)∂2 ˜ ϕ

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SLIDE 7

On the relation between Calogero model and CFT

α0 = √ λ − 1/ √ λ λ(λ − 1) (xi − xj)2 Txy = (∂xϕ)2 + α0∂2

x ˜

ϕ

Flux of energy through the boundary

˙ ϕ = Txy

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SLIDE 8

Period of oscillations is

(interaction) × (δρ)−1 >> k−1

F

Quantum Non-linear Equations can be treated semiclassically

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SLIDE 9

Trigonometric Calogero-Sutherland model Model for edge states of the FQHE

H = − X

i

∂2

i +

X

j

λ(λ − 1) sin2(xi − xj)

HΨ = EΨ

Ψ(x1, . . . , xN) = Y

i>j

(eixi − eixj)λJY (x1, . . . , xN)

Jack symmetric polynomial

λ = 0 − bosons

λ = 1 − fermions

Ψ(...xi...xj...) = e2πiλΨ(...xj...xi...)

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SLIDE 10

H = − X

i

∂2

i +

X

j

λ(λ − 1) sin2(xi − xj)

˙ ϕ = 1 2(∂xϕ)2 + (λ − 1)∂2 ˜ ϕ

ak>0 = X

i

eikxi

[ak, a−k0] = λkδkk0

ϕ(x) = X

k

eikx k ak,

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SLIDE 11

Properties: 1) Integrable (despite being non-local); 2) Its solitons carry a quantized fractional charge:

˙ ϕ + (∂xϕ)2 + ν∂2

xϕH = 0

Z ρdx = Z dϕ = integer × ν

3) Solitons have Lorentzian shape:

ρs(x, t) = 1 π vν v2(x − vt)2 + ν2

Properties of Benjamin-Ono Equation

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SLIDE 12

Soliton - collective excitation of particles

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SLIDE 13

Shock wave:

competition between non-linear term and dispersion term

˙ ϕ + (∂xϕ)2 + ν∂2

xϕH = 0

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SLIDE 14

Long time asymptote: Soliton train

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SLIDE 15

Soliton Train time

space

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SLIDE 16

A single soliton (area is 1/3) 1/4 of quantum (area is 1/12)

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SLIDE 17

N=7 N=20

Soliton trains

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SLIDE 18
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SLIDE 19

Separation between hole (moving right) and particles (moving left)

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SLIDE 20

Conclusions:

1) Dynamics of the edge state is essentially non-linear; 2) Solitons of non-linear dynamics carry fractional charge; 3) A propagation of any front evolves to a shock wave and further in a fractionally quantized soliton train. Quantum shocks in BEC

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SLIDE 21
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SLIDE 22
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SLIDE 23
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SLIDE 24

Quantum Hydrodynamics of Calogero-Sutherland model

˙ xi = pi

˙ pi = X

j

λ(λ − 1) (xi − xj)3

˙ xi = X

k

λ xi − yk − X

k

λ xi − xk

− ˙ yi = X

k

λ yi − xk − X

k

λ yi − yk

pi = X

k

λ xi − yk − X

k

λ xi − xk

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SLIDE 25

˙ xi = X

k

λ xi − yk − X

k

λ xi − xk − ˙ yi = X

k

λ yi − xk − X

k

λ yi − yk ϕ(z) = λ X

i

log(z − xk) + λ X

i

log(z − yk) ˜ ϕ(z) = λ X

i

log(z − xk) − λ X

i

log(z − yk) ˙ ϕ = 1 2(∂xϕ)2 + (λ − 1)∂2 ˜ ϕ

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SLIDE 26

Density and velocity

∂x ≥ ϕ(x + i0) − ϕ(x − i0) ¥ = −2λπρ(x)

∂x ≥ ϕ(x + i0) + ϕ(x − i0) ¥ = v − 2iλ∂x log ρ

˙ ρ + ∂x(ρv) = 0

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SLIDE 27

˙ ρ + ∂x(ρv) = 0

˙ v + ∂x ≥v2 2 + w(ρ) ¥ = 0

w(ρ) = λ2π2 2 ρ2 − λ(λ − 1) 2 1 √ρ∂2

x

√ρ + πλ(λ − 1)∂xρH

ρH(x) = Z coth(x − x0)ρ(x0)dx0

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SLIDE 28

v = λ ≥ πρ + ∂x(log √ρ)H¥

ρt + λ∂x ≥ πρ2 + ρ∂x(log √ρ)H¥ = 0

Chiral reduction

two equations become one

Chiral non-linear equation

ρ ≈ ρ0 + u + . . . ˙ u + uux + (λ − 1)˜ uxx = 0

Benjamin-On equation