Year: 2009
Type: article
Abstract: We study the generation of defects when a quantum spin system is quenched through a multicritical point by changing a parameter of the Hamiltonian as t /τ, where τ is the characteristic timescale of quenching. We argue that when a quantum system is quenched across a multicritical point, the density of defects ( n ) in the final state is not necessarily given by the Kibble–Zurek scaling form n ∼1/τ d ν/( z ν+1) , where d is the spatial dimension, and ν and z are respectively the correlation length and dynamical exponent associated with the quantum critical point. We propose a generalized scaling form of the defect density given by n ∼1/τ d /(2 z 2 ) , where the exponent z 2 determines the behavior of the off-diagonal term of the 2 × 2 Landau–Zener matrix at the multicritical point. This scaling is valid not only at a multicritical point but also at an ordinary critical point.
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1990991887