Non-Classicality Versus Non-Gaussianity of Photon Subtracted Displaced Fock State

Priya Malpani, Kishore Thapliyal, J. Banerji +1 more

Priya Malpani, Kishore Thapliyal, Nasir Alam +3 more

Y. Oulouda, Mohammed El Falaki, Mohammed Daoud A

Deepak Deepak, Arpita Chatterjee

In this paper, a quantitative investigation of the non-classical and quantum non-Gaussian characters of the photon-subtracted displaced Fock state [Formula: see text], where k is the number of photons subtracted and n is Fock parameter, is performed by using a collection of measures like Wigner logarithmic negativity, linear entropy potential, skew information-based measure, and relative entropy of quantum non-Gaussianity. It is noticed that the number of photons subtracted ( k) changes the nonclassicality and quantum non-Gaussianity in a significant amount in the regime of small values of the displacement parameter, whereas the Fock parameter ( n) presents a notable change in the large regime of the displacement parameter. In this respect, the role of the Fock parameter is found to be stronger as compared to the photon subtraction number. Finally, the Wigner function dynamics considering the effects of photon loss channel is used to show that the Wigner negativity can only be detected by highly efficient detectors.

Ho Sy Chuong, Phan Ngoc Duy Tinh, Nguyen Minh Xuan +1 more

ABSTRACT In this paper, we study new non‐Gaussian states known as superpositions of photon‐added and photon‐subtracted displaced Fock states (SPA‐PS‐DFSs). We express the SPA‐PS‐DFSs in terms of displaced Fock states (DFSs) and investigate their Wigner function and nonclassical properties. The obtained results of the Wigner function show that the superposition of photon addition and subtraction can enhance the non‐Gaussian and nonclassical properties of the SPA‐PS‐DFSs. Furthermore, the SPA‐PS‐DFSs exhibit nonclassical features, including higher‐order squeezing and higher‐order antibunching. Notably, these nonclassical characteristics are more enhanced than those of previous states generated solely by adding or subtracting photons to DFSs without superposition. These findings underscore the effectiveness of the superposition technique in enhancing the non‐Gaussian and nonclassical properties of the states.

Deepak Deepak, Arpita Chatterjee

Abstract Performing non-Gaussian operations, namely photon addition, photon subtraction, photon-addition-then-subtraction, photon-subtraction-then-addition can successfully enhance the fidelity of the continuous-variable quantum teleportation. However, a shortcoming of these non-Gaussian resources is that they are probabilistic in nature. In this article, we investigate the success probability of the non-Gaussian resources for optimal performance of the ideal teleportation protocol. To this end, we first derive the analytical expression for the two-mode entangled channel having f-deformed displaced Fock state or photon-added displaced Fock state or photon-subtracted displaced Fock state at one port and vacuum at another port of a symmetric beam-splitter. The generalized displaced Fock states are obtained by replacing the conventional bosonic functions by the nonlinear f-deformed operators such as A = af(a † a) and B = af ( a † a ) − 1 . The Wigner characteristic functions describing these three aforementioned non-Gaussian states are determined and utilized to attain the teleportation fidelity for input coherent and squeezed vacuum states. It is found that the nonlinear substitution leads to an enhancement in teleportation fidelity beyond the threshold limit. Moreover, the entangled photon-subtracted displaced Fock state demonstrates maximum efficiency as a quantum channel for teleporting single-mode coherent and squeezed states. We provide the squeezing regime values corresponding to the optimal performance of the non-Gaussian states considered, which will be of significant interest to the experimental fraternity. Further, we show that the entangled photon-added displaced Fock states have larger amount of entanglement but the entangled photon-subtracted displaced Fock states have stronger Einstein-Podolsky-Rosen correlation.