In quantum optics, nonclassical properties of various quantum states of radiation field are frequently studied. Some of those states are finite dimensional and referred to as qudits. These states are important because of their potential applications in quantum information processing. Further, nonclassical states are those which do not have any classical counterpart. Consequently, to establish quantum supremacy, we always require nonclassical state. Recently, Sivakumar and Meher have studied the nonclassical properties of the number state filtered coherent state, and shown that the number state filtering introduces nonclassical features into coherent state which is otherwise classical. This observation motivated us to investigate the role of hole burning (state filtering) on a state which is already nonclassical. Specifically, we have selected a Binomial state which is known to be nonclassical as our test bed and burnt a hole at vacuum (equivalently filtered the vacuum state). To check the nonclassical properties of vacuum filtered binomial state, we have used Vogel's criterion, criterion of higher- and lower-order antibunching, criterion of higher-order sub-Poissonian photon statistics, Linear entropy etc. The investigation results show that vacuum filtered binomial state studied here is highly nonclassical, and the hole burning process enhances the nonclassical depth.In quantum optics, nonclassical properties of various quantum states of radiation field are frequently studied. Some of those states are finite dimensional and referred to as qudits. These states are important because of their potential applications in quantum information processing. Further, nonclassical states are those which do not have any classical counterpart. Consequently, to establish quantum supremacy, we always require nonclassical state. Recently, Sivakumar and Meher have studied the nonclassical properties of the number state filtered coherent state, and shown that the number state filtering introduces nonclassical features into coherent state which is otherwise classical. This observation motivated us to investigate the role of hole burning (state filtering) on a state which is already nonclassical. Specifically, we have selected a Binomial state which is known to be nonclassical as our test bed and burnt a hole at vacuum (equivalently filtered the vacuum state). To check the nonclassical properties of vacuum filtered binomial state, we have used Vogel's criterion, criterion of higher- and lower-order antibunching, criterion of higher-order sub-Poissonian photon statistics, Linear entropy etc. The investigation results show that vacuum filtered binomial state studied here is highly nonclassical, and the hole burning process enhances the nonclassical depth.

arXiv:2011.11438Nov 20, 20200 citations

Manipulating Nonclassicality via Quantum State Engineering Processes: Vacuum Filtration and Single Photon Addition

Priya Malpani, Nasir Alam, Kishore Thapliyal +3 more

Abstract The effect of two quantum state engineering processes that can be used to burn a hole at vacuum in the photon number distribution of quantum states of radiation field is compared using various witnesses of lower‐ and higher‐order nonclassicality as well as a measure of nonclassicality. Specifically, the modification in nonclassical properties due to vacuum state filtration and a single photon addition on an even coherent state, binomial state, and Kerr state are investigated using the criteria of lower‐ and higher‐order antibunching, squeezing, and sub‐Poissonian photon statistics. Further, the amount of nonclassicality present in these engineered quantum states having enormous applications in continuous variable quantum communication is quantified and analyzed by using an linear entropy‐based entanglement potential. It is observed that all the quantum states studied here are highly nonclassical, and the hole‐burning processes can introduce/enhance nonclassical features. However, it is not true in general. A hole at vacuum implies a maximally nonclassical state (as far as Lee's nonclassical depth is concerned), but a particular process of hole burning at vacuum does not ensure the existence of any particular nonclassical feature. Specifically, lower‐ and higher‐order squeezing are not observed for photon‐added and vacuum filtered even coherent states.Abstract The effect of two quantum state engineering processes that can be used to burn a hole at vacuum in the photon number distribution of quantum states of radiation field is compared using various witnesses of lower‐ and higher‐order nonclassicality as well as a measure of nonclassicality. Specifically, the modification in nonclassical properties due to vacuum state filtration and a single photon addition on an even coherent state, binomial state, and Kerr state are investigated using the criteria of lower‐ and higher‐order antibunching, squeezing, and sub‐Poissonian photon statistics. Further, the amount of nonclassicality present in these engineered quantum states having enormous applications in continuous variable quantum communication is quantified and analyzed by using an linear entropy‐based entanglement potential. It is observed that all the quantum states studied here are highly nonclassical, and the hole‐burning processes can introduce/enhance nonclassical features. However, it is not true in general. A hole at vacuum implies a maximally nonclassical state (as far as Lee's nonclassical depth is concerned), but a particular process of hole burning at vacuum does not ensure the existence of any particular nonclassical feature. Specifically, lower‐ and higher‐order squeezing are not observed for photon‐added and vacuum filtered even coherent states.

arXiv:1907.03257Annalen der PhysikNov 20, 201910 citations

Higher order nonclassicality in single photon added and subtracted binomial state of light

Kathakali Mandal, Amit Verma

In the recent years, effect of photon addition and subtraction to a quantum state of light is explored for coherent state, thermal state, Schrödinger cat state, Gaussian state and many more. It is reported that the phenomena of photon addition or subtraction significantly affect nonclassical properties of the states of light. Here we wish to study the effect of photon addition and subtraction to the binomial start of radiation on the nonclassical properties of the state. We observed that the depth of nonclassicality increases with photon addition and decreases with photon subtraction in antibunching and squeezing phenomenon. We also report significant changes in photon number distribution and variable with depending parameters.In the recent years, effect of photon addition and subtraction to a quantum state of light is explored for coherent state, thermal state, Schrödinger cat state, Gaussian state and many more. It is reported that the phenomena of photon addition or subtraction significantly affect nonclassical properties of the states of light. Here we wish to study the effect of photon addition and subtraction to the binomial start of radiation on the nonclassical properties of the state. We observed that the depth of nonclassicality increases with photon addition and decreases with photon subtraction in antibunching and squeezing phenomenon. We also report significant changes in photon number distribution and variable with depending parameters.

AIP conference proceedingsJan 1, 20191 citation

Number state filtered coherent state

Nilakantha Meher, Sivakumar, S.

Number state filtering in coherent states leads to sub-Poissonian photon statistics. These states are more suitable for phase estimation when compared with the coherent states. Nonclassicality of these states is quantified in terms of the negativity of the Wigner function and the entanglement potential. Filtering of the vacuum from a coherent state is almost like the photon-addition. However, filtering makes the state more resilient against dissipation than photon-addition. Vacuum state filtered coherent states perform better than the photon-added coherent states for a two-way quantum key distribution protocol. A scheme to generate these states in multi-photon atom-field interaction is presented.Number state filtering in coherent states leads to sub-Poissonian photon statistics. These states are more suitable for phase estimation when compared with the coherent states. Nonclassicality of these states is quantified in terms of the negativity of the Wigner function and the entanglement potential. Filtering of the vacuum from a coherent state is almost like the photon-addition. However, filtering makes the state more resilient against dissipation than photon-addition. Vacuum state filtered coherent states perform better than the photon-added coherent states for a two-way quantum key distribution protocol. A scheme to generate these states in multi-photon atom-field interaction is presented.

arXiv:1801.05704Jan 16, 20180 citations

Fock-state filtering of squeezed states: enhanced nonclassicality and effects of a thermal bath

João Pedro Gonzalez de Oliveira, A. Vidiella-Barranco

The ability to tailor photon-number statistics is central to the generation and control of nonclassical states of light. Here, we investigate how Fock-state filtering of squeezed coherent states can be used to engineer their photon statistics. We consider the selective removal of the $m=0$ and $m=1$ Fock components and show that this process can enhance the sub-Poissonian character of the field, depending on the coherent amplitude. We then analyze the evolution of these engineered states in a thermal environment. Although all states eventually relax toward thermal statistics, the signatures of the filtering process may persist over a significant part of the evolution, while the purity of the filtered states is rapidly degraded by incoherent population redistribution. Our results illustrate both the potential and the limitations of photon-number engineering in realistic, dissipative settings.The ability to tailor photon-number statistics is central to the generation and control of nonclassical states of light. Here, we investigate how Fock-state filtering of squeezed coherent states can be used to engineer their photon statistics. We consider the selective removal of the $m=0$ and $m=1$ Fock components and show that this process can enhance the sub-Poissonian character of the field, depending on the coherent amplitude. We then analyze the evolution of these engineered states in a thermal environment. Although all states eventually relax toward thermal statistics, the signatures of the filtering process may persist over a significant part of the evolution, while the purity of the filtered states is rapidly degraded by incoherent population redistribution. Our results illustrate both the potential and the limitations of photon-number engineering in realistic, dissipative settings.

quant-pharXiv:2608.22668Brazilian Journal of PhysicsAug 25, 20260 citations

Lower- versus higher-order nonclassicalities for a coherent superposed quantum state

Deepak Deepak, Arpita Chatterjee

A coherent state is defined conventionally in different ways such as a displaced vacuum state, an eigenket of an annihilation operator, or as an infinite dimensional Poissonian superposition of Fock states. In this work, we describe a superposition ( t a + r a † ) of field annihilation and creation operators acting on a continuous variable coherent state | α ⟩ and specify it by | ψ ⟩ . We analyze the lower- as well as higher-order nonclassical properties of | ψ ⟩ . The comparison is performed by using a set of nonclassicality witnesses (e.g., higher-order photon statistics, higher-order antibunching, higher-order sub-Poissonian statistics, higher-order squeezing, Agarwal–Tara parameter, Klyshko’s condition, and a relatively new concept, matrix of phase-space distribution). It is found that the higher-order criteria are much more efficient to detect the presence of nonclassicality as compared to lower-order conditions except squeezing, where the lower-order one is more competent than its higher-order counterpart.A coherent state is defined conventionally in different ways such as a displaced vacuum state, an eigenket of an annihilation operator, or as an infinite dimensional Poissonian superposition of Fock states. In this work, we describe a superposition ( t a + r a † ) of field annihilation and creation operators acting on a continuous variable coherent state | α ⟩ and specify it by | ψ ⟩ . We analyze the lower- as well as higher-order nonclassical properties of | ψ ⟩ . The comparison is performed by using a set of nonclassicality witnesses (e.g., higher-order photon statistics, higher-order antibunching, higher-order sub-Poissonian statistics, higher-order squeezing, Agarwal–Tara parameter, Klyshko’s condition, and a relatively new concept, matrix of phase-space distribution). It is found that the higher-order criteria are much more efficient to detect the presence of nonclassicality as compared to lower-order conditions except squeezing, where the lower-order one is more competent than its higher-order counterpart.

arXiv:2304.05054Journal of the Optical Society of America BSep 17, 20212 citations

m=0

and

m=1

Fock components and show that this process can enhance the sub-Poissonian character of the field, depending on the coherent amplitude. We then analyze the evolution of these engineered states in a thermal environment. Although all states eventually relax toward thermal statistics, the signatures of the filtering process may persist over a significant part of the evolution, while the purity of the filtered states is rapidly degraded by incoherent population redistribution. Our results illustrate both the potential and the limitations of photon-number engineering in realistic, dissipative settings.