Decoherence dynamics of geometric measure of quantum discord and measurement induced nonlocality for noninertial observers at finite temperature

Abstract

Quantum discord quantifies the total non-classical correlations in mixed states. It is the difference between total correlation, measured by quantum mutual information, and the classical correlation. Another step forward towards the quantification of quantum discord was by Dakic, Vedral, and Brukner [Phys. Rev. Lett. 105,190502 (2010)] who introduced the geometric measure of quantum discord (GMQD) and derived an explicit formula for a two-qubit state. Recently, Luo and Fu [Phys. Rev. Lett. 106, 120401 (2011)] introduced measurement-induced nonlocality (MIN) as a measure of nonlocality for a bipartite quantum system. The dynamics of GMQD is recently considered by Song et al. [arXiv: quant/ph.1203.3356] and Zhang et al. [Eur. Phys. J. D 66, 34 (2012)] for inertial observers. However, the topic requires due attention in noninertial frames, particularly, from the perspective of MIN. Here I consider X-structured bipartite quantum system in noninertial frames and analyze the decoherence dynamics of GMQD and MIN at finite temperature. The dynamics under the influence of amplitude damping, depolarizing and phase flip channels is discussed. It is worth-noting that initial state entanglement plays an important role in bipartite states. It is possible to distinguish the Bell, Werner and general type initial quantum states using GMQD. Sudden transition in the behaviour of GMQD and MIN occurs depending upon the mean photon number of the local environment.The transition behaviour disappears for larger values ofn, i.e.n > 0.3. It becomes more prominent, when environmental noise is introduced in the system. In the presence of environmental noise, as we increase the value of acceleration r, GMQD and MIN decay due to Unruh effect. The effect is prominent for the phase flip and amplitude damping channels.However, in case of depolarizing channel, no sudden change in the behaviour of GMQD and MIN is observed. The environmental noise has stronger affect on the dynamics of GMQD and MIN as compared to the Unruh effect. Furthermore, Werner like states are more robust than General type initial states at finite temperature.

Quantum speed limit time for the damped Jaynes-Cummings and Ohmic-like dephasing models in Schwarzschild space-time

“…So, using the ordinary structure of these two interaction model in Schwarzschild black hole is applicable and logical due to considering Dirac field state instead of bosonic state and applying single-mode aproximation. Actually, in must studies [23,[45][46][47][48][49] the authors use ordinary structure for the generator of the dynamics of the system in Damped Jaynes-Cummings and Ohmic-like dephasing models.…”

Quantum coherence behaviors of fermionic system in non-inertial frame

“…It is believed that the study of quantum correlation in a relativistic setting is not only helpful in understanding some key questions in quantum information theory, but also plays an important role in the study of quantum effects of black holes [6][7][8][9]. Many authors [10][11][12][13][14][15][16][17][18] have studied the behaviors of entanglement and discord-type quantum correlations in fermionic system of non-inertial frames based on single-mode approximation (SMA). Recently, Some papers [19][20][21][22][23][24] consider the behaviors of quantum correlations of fermionic system in accelerated frame beyond SMA.…”

An easy measure of quantum correlation

“…This nonlocal effect, usually called "quantum correlation", cannot be interpreted by any local hidden variable theory and plays the vital role in quantum information processing, such as better-than classical communication and information protocols [1,2], quantum computing without entanglement [3], and nolocal-broadcasting [4]. Furthermore, many evidences show that quantum correlation is more robust than entanglement against decoherence, so that quantum algorithms based on quantum correlation may be more robust than those based on entanglement B Jie-Hui Huang jhhuang@jxnu.edu.cn 1 College of Physics and Communication Electronics, Jiangxi Normal University, Nanchang 330022, China [5][6][7]. In many circumstances, we need to know whether a state can be used in a quantum information task or to what extent a quantum state can help do it.…”