Realizing Non-Gaussian Non-classical States Of Light Field Via Photonic Catalysis

In quantum optics and quantum information science,non-classical properties of light fields,such as anti-bunching,sub-Poissonian statistics,squeezing and negative Wigner functions,have always attracted a lot of attentions.Generically,quantum states of the light fields can be divided into Gaussian states and non-Gaussian states.The former refer to the states whose phase-space distribution functions have Gaussian form,and its Wigner quasi-probability distribution function is positive.While the non-Gaussian states refer to quantum states whose phase-space distribution functions have non-Gaussian form,but with positive or negative Wigner functions.The negative values of the Wigner functions are therefore the important manifestation of non-Gaussian non-classicality.Research has shown that non-Gaussian states can not only improve the efficiency of quantum information processing,such as quantum teleportation,quantum cloning and quantum storage,but also plays a key role in realizing quantum error correction,entanglement distillation and quantum computing.In principle,non-Gaussian non-classical states can be realized through the nonlinear coherent coupling of the system,but it requires nonlinear strong coupling to achieve strong non-classicality.This condition is very harsh and it is generally not easy to be achieved experimentally.In order to solve this problem,it is shown that non-Gaussian states can be effectively realized by using non-Gaussian operations,such as adding and subtracting photons.Based on this,this paper considers the use of photon-catalyzed non-Gaussian operation to realizing non-Gaussian non-classical states of the light.Photon catalysis involves the combination of an input a beam of light in a quantum state |φ>and another beam of light in the N photons Fock state on a beam splitter.When N photons are detected at one output port of the beam splitter,the quantum state of the other output port of the light field can be regarded as the input state |φ>catalyzed by N photons.In this paper,we consider the use of the above-mentioned N photon catalysis to convert the input state |φ>being in a coherent squeezed thermal state(Gaussian state)into a non-Gaussian non-classical state.