Abstract
Non-Gaussianity is an important resource for quantum information processing with continuous variables. We introduce a measure of the non-Gaussianity of bosonic field states based on the Hellinger distance and present its basic features. This measure has some natural properties and is easy to compute. We illustrate this measure with typical examples of bosonic field states and compare it with various measures of non-Gaussianity. In particular, we highlight its similarity to and difference from the measure based on the Bures distance (or, equivalently, fidelity).
Similar content being viewed by others
REFERENCES
G. Giedke and J. I. Cirac, “Characterization of Gaussian operations and distillation of Gaussian states,” Phys. Rev. A, 66, 032316 (2002).
J. Eisert and M. B. Plenio, “Introduction to the basics of entanglement theory in continuous-variable systems,” Internat. J. Quantum Inf., 1, 479–506 (2003).
A. Ferraro, S. Olivares, and M. G. A. Paris, Gaussian States in Quantum Information, Bibliopolis, Napoli (2005).
S. L. Braunstein and P. van Loock, “Quantum information with continuous variables,” Rev. Modern Phys., 77, 513–577 (2005); arXiv:quant-ph/0410100v1 (2004).
X.-B. Wang, T. Hiroshima, A. Tomita, and M. Hayashi, “Quantum information with Gaussian states,” Phys. Rep., 448, 1–111 (2007).
C. Weedbrook, S. Pirandola, R. G. Patrón, N. J. Cerf, T. C. Ralph, J. H. Shapiro, and S. Lloyd, “Gaussian quantum information,” Rev. Modern Phys., 84, 621–669 (2012); arXiv:1110.3234v1 [quant-ph] (2011).
G. Adesso, S. Ragy, and A. R. Lee, “Continuous variable quantum information: Gaussian states and beyond,” Open Syst. Inf. Dyn., 21, 1440001 (2014).
I. E. Segal, “Foundations of the theory of dynamical systems of infinitely many degrees of freedom: II,” Canadian J. Math., 13, 1–18 (1961).
A. S. Holevo, Probabilistic and Statistical Aspects of Quantum Theory [in Russian], MTsNMO, Moscow (2020); English transl. prev. ed., North-Holland, Amsterdam (1982).
R. Simon, “Peres–Horodecki separability criterion for continuous variable systems,” Phys. Rev. Lett., 84, 2726–2729 (2000); arXiv:quant-ph/9909044v1 (1999).
R. Simon, E. C. G. Sudarshan, and N. Mukunda, “Gaussian–Wigner distributions in quantum mechanics and optics,” Phys. Rev. A, 36, 3868–3880 (1987).
S. Fu, S. Luo, and Y. Zhang, “Gaussian states as minimum uncertainty states,” Phys. Lett. A, 384, 126037 (2020).
F. Grosshans, G. Van Assche, J. Wenger, R. Brouri, N. J. Cerf, and P. Grangier, “Quantum key distribution using Gaussian-modulated coherent states,” Nature, 421, 238–241 (2003); arXiv:quant-ph/0312016v1 (2003).
V. D’Auria, S. Fornaro, A. Porzio, S. Solimeno, S. Olivares, and M. G. A. Paris, “Full characterization of Gaussian bipartite entangled states by a single homodyne detector,” Phys. Rev. Lett., 102, 020502 (2009).
D. Daems, F. Bernard, N. J. Cerf, and M. I. Kolobov, “Tripartite entanglement in parametric down-conversion with spatially structured pump,” J. Opt. Soc. Am. B , 27, 447–451 (2010); arXiv:1002.1798v1 [quant-ph] (2010).
L.-M. Duan, G. Giedke, J. I. Cirac, and P. Zoller, “Inseparability criterion for continuous variable systems,” Phys. Rev. Lett., 84, 2722–2725 (2000); arXiv:quant-ph/9908056v2 (1999).
G. Adesso, A. Serafini, and F. Illuminati, “Quantification and scaling of multipartite entanglement in continuous variable systems,” Phys. Rev. Lett., 93, 220504 (2004); arXiv:quant-ph/0406053v2 (2004).
P. Marian and T. A. Marian, “Entanglement of formation for an arbitrary two-mode Gaussian state,” Phys. Rev. Lett., 101, 220403 (2008); arXiv:0809.0321v3 [quant-ph] (2008).
G. Adesso and A. Datta, “Quantum versus classical correlations in Gaussian states,” Phys. Rev. Lett., 105, 030501 (2010); arXiv:1003.4979v2 [quant-ph] (2010).
P. Giorda and M. G. A. Paris, “Gaussian quantum discord,” Phys. Rev. Lett., 105, 020503 (2010); arXiv:1003.3207v2 [quant-ph] (2010).
T. Opatrný, G. Kurizki, and D.-G. Welsch, “Improvement on teleportation of continuous variables by photon subtraction via conditional measurement,” Phys. Rev. A, 61, 032302 (2000).
P. T. Cochrane, T. C. Ralph, and G. J. Milburn, “Teleportation improvement by conditional measurements on the two-mode squeezed vacuum,” Phys. Rev. A, 65, 062306 (2002).
S. Olivares, M. G. A. Paris, and R. Bonifacio, “Teleportation improvement by inconclusive photon subtraction,” Phys. Rev. A, 67, 032314 (2003); arXiv:quant-ph/0209140v2 (2002).
N. J. Cerf, O. Krüger, P. Navez, R. F. Werner, and M. M. Wolf, “Non-Gaussian cloning of quantum coherent states is optimal,” Phys. Rev. Lett., 95, 070501 (2005); arXiv:quant-ph/0410058v2 (2004).
F. Dell’Anno, S. De Siena, L. Albano, and F. Illuminati, “Continuous-variable quantum teleportation with non-Gaussian resources,” Phys. Rev. A, 76, 022301 (2007); arXiv:0706.3701v1 [quant-ph] (2007).
F. Dell’Anno, S. De Siena, and F. Illuminati, “Realistic continuous-variable quantum teleportation with non-Gaussian resources,” Phys. Rev. A, 81, 012333 (2010); arXiv:0910.2713v2 [quant-ph] (2009).
R. Takagi and Q. Zhuang, “Convex resource theory of non-Gaussianity,” Phys. Rev. A, 97, 062337 (2018); arXiv:1804.04669v2 [quant-ph] (2018).
L. Lami, B. Regula, X. Wang, R. Nichols, A. Winter, and G. Adesso, “Gaussian quantum resource theories,” Phys. Rev. A, 98, 022335 (2018); arXiv:1801.0545v1 [cond-mat.supr-con] (2018).
F. Albarelli, M. G. Genoni, M. G. A. Paris, and A. Ferraro, “Resource theory of quantum non-Gaussianity and Wigner negativity,” Phys. Rev. A, 98, 052350 (2018); arXiv:1804.05763v2 [quant-ph] (2018).
R. M. Gomes, A. Salles, F. Toscano, P. H. Souto Ribeiro, and S. P. Walborn, “Quantum entanglement beyond Gaussian criteria,” Proc. Natl. Acad. Sci. USA, 106, 21517–21520 (2009).
M. Allegra, P. Giorda, and M. G. A. Paris, “Role of initial entanglement and non-Gaussianity in the decoherence of photon-number entangled states evolving in a noisy channel,” Phys. Rev. Lett., 105, 100503 (2010).
R. Tatham, L. Mišta Jr., G. Adesso, and N. Korolkova, “Nonclassical correlations in continuous-variable non-Gaussian Werner states,” Phys. Rev. A, 85, 022326 (2012); arXiv:1111.1101v2 [quant-ph] (2011).
C. Navarrete-Benlloch, R. Garc\’ia-Patrón, J. H. Shapiro, and N. J. Cerf, “Enhancing quantum entanglement by photon addition and subtraction,” Phys. Rev. A, 86, 012328 (2012); arXiv:1201.4120v2 [quant-ph] (2012).
K. K. Sabapathy and A. Winter, “Non-Gaussian operations on bosonic modes of light: Photon-added Gaussian channels,” Phys. Rev. A, 95, 062309 (2017); arXiv:1604.07859v4 [quant-ph] (2016).
M. Barbieri, N. Spagnolo, M. G. Genoni, F. Ferreyrol, R. Blandino, M. G. A. Paris, P. Grangier, and R. Tualle-Brouri, “Non-Gaussianity of quantum states: An experimental test on single-photon-added coherent states,” Phys. Rev. A, 82, 063833 (2010); arXiv:1012.0466v1 [quant-ph] (2010).
A. Allevi, S. Olivares, and M. Bondani, “Manipulating the non-Gaussianity of phase-randomized coherent states,” Opt. Exp., 20, 24850–24855 (2012); arXiv:1210.0303v1 [physics.optics] (2012).
C. Baune, A. Schönbeck, A. Samblowski, J. Fiurášek, and R. Schnabel, “Quantum non-Gaussianity of frequency up-converted single photons,” Opt. Exp., 22, 22808–22816 (2014); arXiv:1406.1602v3 [quant-ph] (2014).
C. Hughes, M. G. Genoni, T. Tufarelli, M. G. A. Paris, and M. S. Kim, “Quantum non-Gaussianity witnesses in phase space,” Phys. Rev. A, 90, 013810 (2014); arXiv:1403.6264v2 [quant-ph] (2014).
R. Filip and L. Mišta Jr., “Detecting quantum states with a positive Wigner function beyond mixtures of Gaussian states,” Phys. Rev. Lett., 106, 200401 (2011).
M. G. Genoni, M. L. Palma, T. Tufarelli, S. Olivares, M. S. Kim, and M. G. A. Paris, “Detecting quantum non-Gaussianity via the Wigner function,” Phys. Rev. A, 87, 062104 (2013); arXiv:1304.3340v2 [quant-ph] (2013).
I. Straka, A. Predojević, T. Huber, L. Lachman, L. Butschek, M. Miková, M. Mičuda, G. S. Solomon, G. Weihs, M. Ježek, and R. Filip, “Quantum non-Gaussian depth of single-photon states,” Phys. Rev. Lett., 113, 223603 (2014); arXiv:1403.4194v2 [quant-ph] (2014).
M. G. Genoni, M. G. A. Paris, and K. Banaszek, “Measure of the non-Gaussian character of a quantum state,” Phys. Rev. A, 76, 042327 (2007); arXiv:0704.0639v4 [quant-ph] (2007).
M. G. Genoni, M. G. A. Paris, and K. Banaszek, “Quantifying the non-Gaussian character of a quantum state by quantum relative entropy,” Phys. Rev. A, 78, 060303 (2008); arXiv:0805.1645v4 [quant-ph] (2008).
M. G. Genoni and M. G. A. Paris, “Quantifying non-Gaussianity for quantum information,” Phys. Rev. A, 82, 052341 (2010); arXiv:1008.4243v3 [quant-ph] (2010).
P. Marian and T. A. Marian, “Relative entropy is an exact measure of non-Gaussianity,” Phys. Rev. A, 88, 012322 (2013); arXiv:1308.2939v1 [quant-ph] (2013).
J. S. Ivan, M. S. Kumar, and R. Simon, “A measure of non-Gaussianity for quantum states,” Quantum Inf. Process., 11, 853–872 (2012).
I. Ghiu, P. Marian, and T. A. Marian, “Measures of non-Gaussianity for one-mode field states,” Phys. Scr., T153, 014028 (2013); arXiv:1210.1929v1 [quant-ph] (2012).
P. Marian, I. Ghiu, and T. A. Marian, “Gaussification through decoherence,” Phys. Rev. A, 88, 012316 (2013); arXiv:1211.1701v3 [quant-ph] (2012).
W. Son, “Role of quantum non-Gaussian distance in entropic uncertainty relations,” Phys. Rev. A, 92, 012114 (2015); arXiv:1504.05725v1 [quant-ph] (2015).
K. Baek and H. Nha, “Non-Gaussianity and entropy-bounded uncertainty relations: Application to detection of non-Gaussian entangled states,” Phys. Rev. A, 98, 042314 (2018); arXiv:1811.10207v1 [quant-ph] (2018).
S. Fu, S. Luo, and Y. Zhang, “Quantifying non-Gaussianity of bosonic fields via an uncertainty relation,” Phys. Rev. A, 101, 012125 (2020).
P. Marian and T. A. Marian, “Hellinger distance as a measure of Gaussian discord,” J. Phys. A: Math. Theor., 48, 115301 (2015); arXiv:1408.4477v2 [quant-ph] (2014).
S. Luo and Q. Zhang, “Informational distance on quantum-state space,” Phys. Rev. A, 69, 032106 (2004).
P. Marian and T. A. Marian, “Squeezed states with thermal noise: I. Photon-number statistics,” Phys. Rev. A, 47, 4474–4486 (1993); “Squeezed states with thermal noise: II. Damping and photon counting,” Phys. Rev. A, 47, 4487–4495 (1993).
D. Bures, “An extension of Kakutani’s theorem on infinite product measures to the tensor product of semifinite \(W^*\)-algebras,” Trans. Amer. Math. Soc., 135, 199–212 (1969).
M. A. Nielsen and I. L. Chuang, Quantum Computation and Quantum Information, Cambridge Univ. Press, Cambridge (2010).
G. B. Folland, Harmonic Analysis in Phase Space (Annals Math. Stud., Vol. 122), Princeton Univ. Press, Princeton, N. J. (1989).
S. Olivares and M. G. A. Paris, “Photon subtracted states and enhancement of nonlocality in the presence of noise,” J. Opt. B, 7, S392–S397 (2005).
K. K. Sabapathy and C. Weedbrook, “ON states as resource units for universal quantum computation with photonic architectures,” Phys. Rev. A, 97, 062315 (2018); arXiv:1802.05220v2 [quant-ph] (2018).
V. V. Dodonov, O. V. Man’ko, V. I. Man’ko, and A. Wünsche, “Hilbert–Schmidt distance and non-classicality of states in quantum optics,” J. Modern Opt., 47, 633–654 (2000).
M. Ozawa, “Entanglement measures and the Hilbert–Schmidt distance,” Phys. Lett. A, 268, 158–160 (2000).
J. Lee, M. S. Kim, and Č. Brukner, “Operationally invariant measure of the distance between quantum states by complementary measurements,” Phys. Rev. Lett., 91, 087902 (2003); arXiv:quant-ph/0303111v2 (2003).
V. Vedral, “The role of relative entropy in quantum information theory,” Rev. Modern Phys., 74, 197–234 (2002).
A. Wehrl, “General properties of entropy,” Rev. Modern Phys., 50, 221–260 (1978).
A. Wehrl, “On the relation between classical and quantum mechanical entropy,” Rep. Math. Phys., 16, 353–358 (1979).
E. H. Lieb, “Proof of an entropy conjecture of Wehrl,” Commun. Math. Phys., 62, 35–41 (1978).
A. Orłowski, “Classical entropy of quantum states of light,” Phys. Rev. A, 48, 727–731 (1993).
S. Luo, “A simple proof of Wehrl’s conjecture on entropy,” J. Phys. A: Math. Gen., 33, 3093–3096 (2000).
F. Mintert and K. Życzkowski, “Wehrl entropy, Lieb conjecture, and entanglement monotones,” Phys. Rev. A, 69, 022317 (2004); arXiv:quant-ph/0307169v2 (2003).
Funding
This research was supported by the National Natural Science Foundation of China (Grant No. 11875317), the National Center for Mathematics and Interdisciplinary Sciences, Chinese Academy of Sciences (Grant No. Y029152K51), and the Key Laboratory of Random Complex Structures and Data Science, Chinese Academy of Sciences (Grant No. 2008DP173182).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
The authors declare no conflicts of interest.
Rights and permissions
About this article
Cite this article
Zhang, Y., Luo, S. Quantifying non-Gaussianity via the Hellinger distance. Theor Math Phys 204, 1046–1058 (2020). https://doi.org/10.1134/S0040577920080061
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0040577920080061