I explore entanglement dynamics in a three qubit system comparing the ability of entanglement witnesses to detect tripartite entanglement to the phenomenon of entanglement sudden death (ESD). Using a system subject to dephasing I invoke entanglement witnesses to detect tripartite Greenberger-Horne-Zeilinger (GHZ)-type and $W$ -type entanglement and compare the evolution of their detection capabilities with the evolution of the negativity, bipartite concurrence, and tripartite negativity. Interestingly, I find a state in which there is no concurrence or tripartite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction code to address how ESD affects the abilities of quantum error correction.I explore entanglement dynamics in a three qubit system comparing the ability of entanglement witnesses to detect tripartite entanglement to the phenomenon of entanglement sudden death (ESD). Using a system subject to dephasing I invoke entanglement witnesses to detect tripartite Greenberger-Horne-Zeilinger (GHZ)-type and $W$-type entanglement and compare the evolution of their detection capabilities with the evolution of the negativity, bipartite concurrence, and tripartite negativity. Interestingly, I find a state in which there is no concurrence or tripartite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction code to address how ESD affects the abilities of quantum error correction.

arXiv:0812.4612Physical Review AJan 16, 200979 citations

Yang–Baxter equations and quantum entanglements

Mo‐Lin Ge, Kang Xue, Ruo-Yang Zhang +1 more

Quantum Information ProcessingJul 4, 201414 citations

Delayed sudden death of entanglement at exceptional points

Subhadeep Chakraborty, Amarendra K. Sarma

Almost a decade ago, physicists encountered a strange quantum phenomenon that predicts an unusual death of entanglement, under the influence of a local noisy environment, known as entanglement sudden death (ESD). This could be an immediate stumbling block in realizing all entanglement based quantum information and computation protocols. In this paper, we propose a scheme to tackle such shortcomings by exploiting the phenomenon of exceptional points. Starting with a binary mechanical $\mathcal{PT}$ symmetric system, realized over an optomechanical platform, we show that a substantial delay in ESD can be achieved via pushing the system towards an exceptional point. This finding has been further extended to a higher-order (third-order) exceptional point by taking a more complicated tripartite entanglement into account.Almost a decade ago, physicists encountered a strange quantum phenomenon that predicts an unusual death of entanglement, under the influence of a local noisy environment, known as entanglement sudden death (ESD). This could be an immediate stumbling block in realizing all entanglement based quantum information and computation protocols. In this paper, we propose a scheme to tackle such shortcomings by exploiting the phenomenon of exceptional points. Starting with a binary mechanical $\mathcal{PT}$ symmetric system, realized over an optomechanical platform, we show that a substantial delay in ESD can be achieved via pushing the system towards an exceptional point. This finding has been further extended to a higher-order (third-order) exceptional point by taking a more complicated tripartite entanglement into account.

arXiv:1906.00222Physical Review ADec 27, 201950 citations

W

-type entanglement and compare the evolution of their detection capabilities with the evolution of the negativity, bipartite concurrence, and tripartite negativity. Interestingly, I find a state in which there is no concurrence or tripartite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction code to address how ESD affects the abilities of quantum error correction.

\mathcal{PT}

symmetric system, realized over an optomechanical platform, we show that a substantial delay in ESD can be achieved via pushing the system towards an exceptional point. This finding has been further extended to a higher-order (third-order) exceptional point by taking a more complicated tripartite entanglement into account.