N ON - EQUILIBRIUM DYNAMIC CRITICAL SCALING OF THE QUANTUM I SING CHAIN Michael Kolodrubetz Princeton University In collaboration with: Bryan Clark, David Huse David Pekker Krishnendu Sengupta
Q UANTUM STATE OF TRANSVERSE - FIELD I SING MODEL DURING SLOW RAMP IS … Universal Non-equilibrium Experimentally viable Non-thermal Dephasing resistant
C LASSICAL P HASE T RANSITIONS “Magnetization” Landau-Ginzburg functional
C LASSICAL P HASE T RANSITIONS “Magnetization”
Thermal fluctuations C LASSICAL P HASE T RANSITIONS
Q UANTUM P HASE T RANSITIONS One-dimensional transverse-field Ising chain
Q UANTUM P HASE T RANSITIONS One-dimensional transverse-field Ising chain Paramagnet (PM) Ferromagnet (FM)
Q UANTUM P HASE T RANSITIONS One-dimensional transverse-field Ising chain Paramagnet (PM) Ferromagnet (FM) Quantum fluctuations
C RITICAL S CALING [Smirnov, php.math.unifi.it/users/paf/ LaPietra/files/Chelkak01.ppt]
C RITICAL S CALING [Smirnov, php.math.unifi.it/users/paf/ LaPietra/files/Chelkak01.ppt]
C RITICAL S CALING Correlation length critical exponent Dynamic critical exponent, [Smirnov, php.math.unifi.it/users/paf/ LaPietra/files/Chelkak01.ppt]
C RITICAL S CALING, Ising: Correlation length critical exponent Dynamic critical exponent
C RITICAL S CALING, Ising: Correlation length critical exponent Dynamic critical exponent Order parameter critical exponent
C RITICAL S CALING, Ising: Correlation length critical exponent Dynamic critical exponent Order parameter critical exponent
K IBBLE -Z UREK RAMPS Ramp rate
K IBBLE -Z UREK RAMPS Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS METHODIDEAWHEN IT WORKS “Old-school” Kibble-Zurek [Kibble 1976, Zurek 1985] and set the “interesting” time and length scales -Ramp to the QCP -Ramp to deep in the FM phase
K IBBLE -Z UREK RAMPS METHODIDEAWHEN IT WORKS “Old-school” Kibble-Zurek [Kibble 1976, Zurek 1985] and set the “interesting” time and length scales -Ramp to the QCP -Ramp to deep in the FM phase Kibble-Zurek scaling [Deng et. al. 2008, Erez et. al., in prep., Polkovnikov, …] Most quantities show scaling collapse when scaled by and Throughout the ramp
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate
T RANSVERSE - FIELD I SING CHAIN Sachdev: “Quantum Phase Transitions”
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Quadratic Integrable Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Quadratic Integrable Hamiltonian conserves parity for each mode k Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Quadratic Integrable Hamiltonian conserves parity for each mode k Work in subspace where parity is even Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN Wigner fermionize Quadratic Integrable Hamiltonian conserves parity for each mode k Work in subspace where parity is even Sachdev: “Quantum Phase Transitions” phase
T RANSVERSE - FIELD I SING CHAIN
Low energy, long wavelength theory
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate Low energy, long wavelength theory?
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate Low energy, long wavelength theory
K IBBLE -Z UREK RAMPS Adiabatic Impulse Ramp rate Low energy, long wavelength theory
K IBBLE -Z UREK SCALING LIMIT Schrödinger Equation OR Observable Fixed
K IBBLE -Z UREK SCALING LIMIT
K IBBLE -Z UREK OBSERVABLES Excess heat Spin-spin correlation function
K IBBLE -Z UREK OBSERVABLES Excess heat Spin-spin correlation function
K IBBLE -Z UREK OBSERVABLES
F INITE - SIZE SCALING
Finite size effects can be ignored
F INITE - SIZE SCALING
E QUILIBRIUM VIA DYNAMICS KZ scaling function Equilibrium scaling function If dynamic scaling functions exist, they must have the equilibrium critical exponents
F INITE - SIZE SCALING
L ANDAU -Z ENER DYNAMICS
F INITE - SIZE SCALING
L ANDAU -Z ENER DYNAMICS
A THERMAL PROPERTIES
Inverted
A THERMAL PROPERTIES Kibble-Zurek
A THERMAL PROPERTIES Kibble-Zurek Thermal
D EPHASING Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING Protocol Ramp to create excitations Freeze the Hamiltonian Wait … …
D EPHASING … … Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING … … Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING … … Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING … … Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING Dephasing in integrable model: Generalized Gibb’s ensemble (GGE) … … Protocol Ramp to create excitations Freeze the Hamiltonian Wait
D EPHASING Dephasing in integrable model: Generalized Gibb’s ensemble (GGE) … … Does dephasing occur during the Kibble- Zurek ramp?
D EPHASING Dephasing in integrable model: Generalized Gibb’s ensemble (GGE) … …
D EPHASING Dephasing in integrable model: Generalized Gibb’s ensemble (GGE) as … …
D EPHASING Dephasing in integrable model: Generalized Gibb’s ensemble (GGE) as … …
D EPHASING Cubic ramp: … …
D EPHASING Cubic ramp: as … …
D EPHASING Cubic ramp: as … …
U NIVERSALITY
Additional terms change (renormalize) the non- universal aspects of the critical point They do not change critical scaling Critical exponents Scaling functions Debated for non-integrable system dynamics
U NIVERSALITY
Paramagnet Antiferromagnet
U NIVERSALITY Paramagnet Antiferromagnet Ramp the tilt ( ) linearly in time
U NIVERSALITY
C ONCLUSIONS Solved dynamic critical scaling behavior of the TFI chain Athermal negative correlations Phase-locked high order ramps Strong numerical evidence for universality Tilted boson model has same scaling functions Experimentally accessible Athermal features robust against open boundary conditions Open b.c. simplifies measurement Time scales already available [Simon et. al., 2007]
D EPHASING VIA QUASIPARTICLES
O PEN BOUNDARY CONDITIONS
U NIVERSALITY Remove spin ups on neighboring sites