Effect of parity-time symmetric operation on quantum entanglement

Abstract In this work, we investigate effect of parity-time ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">PT</mml:mi> </mml:mrow> </mml:mrow> </mml:math> ) symmetric operation on the dynamic behavior of entanglement for two qubits system in Markovian and non-Markovian regimes with the resonant and off-resonant cases. First we derive the explicit expressions of concurrence quantifying entanglement for an exactly solving model consisting of two qubits interacting with independent structured reservoir. Then, we give two schemes, i.e. pre- and post- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">PT</mml:mi> </mml:mrow> </mml:mrow> </mml:math> symmetric operations, to show the performance of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">PT</mml:mi> </mml:mrow> </mml:mrow> </mml:math> symmetric operation on entanglement dynamics of two qubits. By investigation, we find that the lower the absolute value of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">PT</mml:mi> </mml:mrow> </mml:mrow> </mml:math> operation strength, the better the enhancement of entanglement. In addition, we show that the entanglement can be obviously enhanced by means of the pre- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">PT</mml:mi> </mml:mrow> </mml:mrow> </mml:math> symmetric operation in different regimes.