TY - JOUR
T1 - Classical and quantum correlations of scalar field in the inflationary universe
AU - Nambu, Yasusada
AU - Ohsumi, Yuji
PY - 2011/8/8
Y1 - 2011/8/8
N2 - We investigate classical and quantum correlations of a quantum field in the inflationary universe using a particle detector model. By considering the entanglement and correlations between two comoving detectors interacting with a scalar field, we find that the entanglement between the detectors becomes zero after their physical separation exceeds the Hubble horizon. Furthermore, the quantum discord, which is defined as the quantum part of total correlation, approaches zero on the super horizon scale. These behaviors support the appearance of the classical nature of the quantum fluctuation generated during the inflationary era.
AB - We investigate classical and quantum correlations of a quantum field in the inflationary universe using a particle detector model. By considering the entanglement and correlations between two comoving detectors interacting with a scalar field, we find that the entanglement between the detectors becomes zero after their physical separation exceeds the Hubble horizon. Furthermore, the quantum discord, which is defined as the quantum part of total correlation, approaches zero on the super horizon scale. These behaviors support the appearance of the classical nature of the quantum fluctuation generated during the inflationary era.
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U2 - 10.1103/PhysRevD.84.044028
DO - 10.1103/PhysRevD.84.044028
M3 - Article
AN - SCOPUS:80052701008
SN - 1550-7998
VL - 84
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 4
M1 - 044028
ER -