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Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
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Conformal Fields and Operator Product Expansion in Critical Quantum Spin Chains.
Yijian Zou1,2, Ashley Milsted1, Guifre Vidal1
1Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
Physical Review Letters
|February 15, 2020
Summary
Researchers developed a variational method to approximate conformal field theory (CFT) operators from quantum spin chains. This approach numerically computes operator product expansion coefficients, enabling the extraction of universality classes for phase transitions.
Area of Science:
- Condensed Matter Physics
- Quantum Field Theory
Background:
- Quantum critical points in quantum spin chains are described by conformal field theory (CFT).
- Extracting CFT conformal data from microscopic Hamiltonians is crucial for understanding universality classes.
Purpose of the Study:
- To develop a variational method for constructing lattice representations of CFT primary operators.
- To numerically compute operator product expansion (OPE) coefficients from these lattice operators.
- To implement Cardy's program for determining universality classes from microscopic models.
Main Methods:
- A variational method is proposed to build approximate lattice representations of primary CFT operators.
- Numerical computation of operator product expansion coefficients is demonstrated.
- The method is applied to a critical quantum Ising model.
Main Results:
- Successful construction of approximate lattice CFT operators.
- Numerical calculation of OPE coefficients for primary fields.
- Demonstration of the method's applicability to generic critical lattice Hamiltonians.
Conclusions:
- The study successfully implements Cardy's program by bridging microscopic Hamiltonians and CFT conformal data.
- This variational approach provides a pathway to extract universality class information from critical quantum systems.
- The method is general and applicable beyond integrable models.
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