Efficient preparation of Greenberger–Horne–Zeilinger state and W state of atoms with the help of the controlled phase flip gates in quantum nodes connected by collective-noise channels

Abstract

Noise plays a troublesome role for entanglement generation, because the polarization entanglement of photons can be easily disturbed by the noise. In this paper, we propose a protocol to prepare Greenberger–Horne–Zeilinger state and W state of atoms in quantum nodes connected by collective-noise channels assisted by quantum nondemolition detectors (QNDs) and the controlled phase flip gates. The frequency degrees of freedom are exploited in our protocol. The successful probability of our protocol can reach 100% neglecting the photon loss and assuming that the efficiency of QNDs is 1. Moreover, the number of times of using QNDs is limited, and this makes the protocol quite effective when collective noise is small.

Keywords:

• Greenberger–Horne–Zeilinger state
• W state
• quantum nondemolition detector
• collective-noise channel

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 11047122] and [grant number 11105030]; the Natural Science Foundation of Fuzhou University of China [grant number XRC-0976] and [grant number 2010-XQ-28]; the SRTP Foundation of China [grant number 201410386024]; the funds from Education Department of Fujian Province of China [grant number JA11005], [grant number JA10009] and [grant number JA10039]; the National Natural Science Foundation of Fujian Province of China [grant number 2010J01006] and [grant number 2012J01269]; the Foundation of Ministry of Education of China [grant number 212085].