Performance improvement of continuous-variable quantum key distribution via photon subtraction

Abstract

It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We propose here a method to improve the performance of entanglement-based (EB) continuous-variable quantum-key-distribution protocol by using the non-Gaussian operation, in particular, the subtraction operation, which can be implemented under current technology easily. Security analysis shows that the subtraction operation can well increase the secure distance and tolerable excess noise of the EB scheme and also the corresponding prepare-and-measure scheme.

Coherence-assisted non-Gaussian measurement-device-independent quantum key distribution

“…Furthermore, in the limit d → 0 ∀ k = 0, the covariance matrix of PSTMSC represents photon subtraction on the TMSV state. This specific case has already been studied extensively in several CV-MDI-QKD protocols [39,42]. Particularly, the previous result on photon subtraction on TMSV is re-examined as a special case of ours.…”

New quantum dialogue protocol based on continuous-variable two-mode squeezed vacuum states

“…And continuous-variable quantum key distribution can resist many kinds of attacks, such as disturbance attack, manin-the-middle attack, entanglement-and-measure attack. Due to the advantages of continuous-variable quantum states, the continuous-variable quantum communication has attracted a lot of attention in both theoretical and experimental aspects in recent years [14][15][16][17][18][19][20][21][22][23][24][25]. Jouguet et al [14] overcame all previous limitations and demonstrated for the first time continuous-variable quantum key distribution over 80 km of optical fiber.…”

“…Furrer et al [17] proposed a method to improve the performance of entanglement-based continuous-variable quantum key distribution protocol by using the non-Gaussian operation, especially the subtraction operation. It is shown that the security of the reverse reconciliation CV-QKD protocols is very sensitive to the noise of coherent source for both the homodyne and heterodyne detections [18,19]. Wang T showed that the noiseless linear amplifier can compensate the detrimental effect of the preparation noise with an enhancement of the maximum transmission distance and the noise resistance [20,21].…”

Nonclassicality generated by repeatedly operating photon annihilation-then-creation and creation-then-annihilation on squeezed vacuum

“…It is shown that these operations enable us to generate highly nonclassical quantum states [8], such as photon-addition coherent state, photon-added thermal states [9][10][11], photon-subtracted squeezed states [12,13], and so on. In addition, single photon operations such as photon subtraction and addition can enhance quantum linear amplifier [14], continuousvariable quantum key distribution [15], entanglement [16][17][18][19], nonlocality [21][22][23], multipartite quantum correlation [20], and the fidelity of continuous variable teleportation [24][25][26]. The entanglement distillation can also be achieved by performing photon subtraction or addition combined with coherent displacement or local squeezing [27][28][29].…”