引入了高阶非经典性的广义概念(用高阶矩表示)。在此广义高阶非经典性框架下,导出了高阶压缩和高阶亚泊松光子统计的条件。在此框架下,利用我们在[J. Phys. A. 33(2000)5607]。它也推广到多光子玻色算子的Brandt和Greenberg。类似地,利用数的高次幂算符的正规序导出了高阶次泊松光子统计的条件。进一步,借助于简单的密度矩阵,证明了高阶反聚束(HOA)和高阶次泊松光子统计(HOSPS)不是同一现象的表现,因而用高阶反聚束条件作为HOSPS的检验是不正确的.它还表明,HOA和HOSPS可能存在,即使在相应的低阶现象的情况下。以二项式态、非线性一阶激发压缩态(NLESS)和非线性真空压缩态(NLVSS)作为量子态的例子,指出这些态可能具有高阶非经典特性。观察到总是反聚束的二项式态并不总是高阶压缩的,而表现出高阶压缩的NLVSS态并不表现出HOSPS和HOA。在NLESS中观察到相反的情况,因此确定HOSPS和HOS是两个独立的高阶非经典签名
英文摘要:
A generalized notion of higher order nonclassicality (in terms of higher order moments) is introduced. Under this generalized framework of higher order nonclassicality, conditions of higher order squeezing and higher order subpoissonian photon statistics are derived. A simpler form of the Hong-Mandel higher order squeezing criterion is derived under this framework by using an operator ordering theorem introduced by us in [J. Phys. A. 33 (2000) 5607]. It is also generalized for multi-photon Bose operators of Brandt and Greenberg. Similarly, condition for higher order subpoissonian photon statistics is derived by normal ordering of higher powers of number operator. Further, with the help of simple density matrices, it is shown that the higher order antibunching (HOA) and higher order subpoissonian photon statistics (HOSPS) are not the manifestation of the same phenomenon and consequently it is incorrect to use the condition of HOA as a test of HOSPS. It is also shown that the HOA and HOSPS may exist even in absence of the corresponding lower order phenomenon. Binomial state, nonlinear first order excited squeezed state (NLESS) and nonlinear vacuum squeezed state (NLVSS) are used as examples of quantum state and it is shown that these states may show higher order nonclssical characteristics. It is observed that the Binomial state which is always antibunched, is not always higher order squeezed and NLVSS which shows higher order squeezing does not show HOSPS and HOA. The opposite is observed in NLESS and consequently it is established that the HOSPS and HOS are two independent signatures of higher order nonclassicality
Dynamics of nonclassicality in a generalized Tavis Cummings model with XY spin $(1/2,1)$ atomic interactions
Faculty of Sciences, Mohammed V University in Rabat(拉巴特穆罕默德五世大学理学院);Centre of Physics and Mathematics, CPM, Faculty of Sciences, Mohammed V University in Rabat(拉巴特穆罕默德五世大学理学院物理与数学中心)
Lower- and higher-order nonclassicality in a Bose-condensed optomechanical-like system and a Fabry-Perot cavity with one movable mirror: squeezing, antibunching and entanglement
Theory-independent monitoring of the decoherence of a superconducting qubit with generalized contextuality
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences(奥地利科学院量子光学与量子信息研究所);Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna(维也纳大学物理学院维也纳量子科学与技术中心);Department of Physics, ETH Zürich(苏黎世联邦理工学院物理系);Perimeter Institute for Theoretical Physics(基础物理研究所)
Higher-order nonclassical effects in fluctuating-loss channels
研究了大气起伏损耗信道中高阶非经典性和纠缠准则的演化。通过制定的矩量矩阵的输入输出关系,我们调查的影响,这样的通道上相应的量子化标准。本文推广了我们以前关于高斯纠缠的工作[M. Bohmann等人,Phys. Rev. A 94,010302(R)(2016)]不仅利用了基于二阶的场景,而且还提供了对非高斯和多模辐射场中经历波动衰减的非经典性和纠缠的详细研究。也就是说,详细研究了标准和状态的各种示例,意外效果,例如,发现了压缩转移对相干位移的依赖性,并证明了非高斯纠缠比高斯纠缠更能抵抗大气损耗.此外,我们提出了一种检测方案,用于测量通过大气传播后的考虑时刻。因此,我们的研究结果可能有助于开发,改进和优化非高斯量子光源在自由空间量子通信中的应用。
Higher Order Squeezing and Higher Order Subpoissonian Photon Statistics in Intermediate States
最近,我们提出了Hong-Mandel高阶压缩和高阶亚泊松光子统计的更简单的判据[Phys.Lett. A 374(2010)1009]。本文利用这些简化的判据研究了在不同的中间态,如广义二项式态、超几何态、负二项式态和加光子相干态中观测HOSPS和HOS的可能性。结果表明,这些态可以满足HOS和HOSPS条件。它还表明,非经典的深度和区域可以通过控制各种参数有关的中间状态。此外,我们还分析了高阶非经典性的不同签名之间的相互关系,参考这些中间状态。我们观察到,在不存在HOS的情况下,广义二项式态可以显示出HOSPS的特征。前面我们已经证明了NLVSS在没有HOSPS的情况下显示了HOS。从而证明了同阶的HOSPS和HOS是相互独立的现象。
Nonclassical features in higher-dimensional systems through logical qudits
在最近的工作[S。阿斯塔纳New Journal of Physics 24.5(2022):053026],我们已经展示了多量子比特系统中不同非经典关联的相互关系,其中量子相干性在单个逻辑量子比特中。在这项工作中,我们将其推广到高维系统。为此,我们根据逻辑量和逻辑连续变量系统的组成物理量和物理连续变量系统采取不同的选择。此后,我们显示的条件之间的相互作用的一致性(在逻辑量子和逻辑CV系统)和条件的非定域性和纠缠(在其基本组成量子和CV系统)。这表明,一个单一的非经典条件检测不同类型的非经典在不同的物理系统。因此,它反映了属于不同维数的希尔伯特空间的状态的不同非经典特征的相互关系。