Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum metrology at the limit with extremal Majorana constellations

Bouchard, F., de la Hoz, P., Gunnar G. Bjork, Robert W. Boyd, Markus Grassl, Z. Hradil, Ebrahim Karimi, A. B. Klimov, Gerd Leuchs, Jaroslav Řeháček, Luis Lorenzo Sánchez-Soto

Published Jan 1, 2017• 37 citations
OpenAlex

Abstract

Quantum metrology allows for a tremendous boost in the accuracy of measurement of diverse physical parameters. The estimation of a rotation constitutes a remarkable example of this quantum-enhanced precision. The recently introduced Kings of Quantumness are especially germane for this task when the rotation axis is unknown, as they have a sensitivity independent of that axis and they achieve a Heisenberg-limit scaling. Here, we report the experimental realization of these states by generating up to 21-dimensional orbital angular momentum states of single photons, and confirm their high metrological abilities. (C) 2017 Optical Society of America.

Related papers

Quantum metrology at the limit with extremal Majorana constellations

F. Bouchard, P. de la Hoz, Gunnar G. Bjork +8 more

Quantum metrology allows for a tremendous boost in the accuracy of measurement of diverse physical parameters. The estimation of a rotation constitutes a remarkable example of this quantum-enhanced precision. The recently introduced Kings of Quantumness are especially germane for this task when the rotation axis is unknown, as they have a sensitivity independent of that axis and they achieve a Heisenberg-limit scaling. Here, we report the experimental realization of these states by generating up to 21-dimensional orbital angular momentum states of single photons, and confirm their high metrological abilities.

arXiv:1612.06804•Optica•Nov 16, 2017•52 citations

Robust quantum metrology with random Majorana constellations

Aaron Z. Goldberg, Jose R Hervas, Ángel S. Sanz +8 more

Abstract Even the most classical states are still governed by quantum theory. A number of physical systems can be described by their Majorana constellations of points on the surface of a sphere, where concentrated constellations and highly symmetric distributions correspond to the least and most quantum states, respectively. If these points are chosen randomly, how quantum will the resultant state be, on average? We explore this simple conceptual question in detail, investigating the quantum properties of the resulting random states. We find these states to be far from the norm, even in the large-number-of-particles limit, where classical intuition often replaces quantum properties, making random Majorana constellations peculiar and intriguing. Moreover, we study their usefulness in the context of rotation sensing and find numerical evidence of their robustness against dephasing and particle loss. We realize these states experimentally using light’s orbital angular momentum degree of freedom and implement arbitrary unitaries with a multiplane light conversion setup to demonstrate the rotation sensing. Our findings open up new possibilities for quantum-enhanced metrology.

arXiv:2112.01612•Quantum Science and Technology•Dec 5, 2024•4 citations

Experimental metrology beyond the standard quantum limit for a wide resources range

Valeria Cimini, Emanuele Polino, Federico Belliardo +5 more

Abstract Adopting quantum resources for parameter estimation discloses the possibility to realize quantum sensors operating at a sensitivity beyond the standard quantum limit. Such an approach promises to reach the fundamental Heisenberg scaling as a function of the employed resources N in the estimation process. Although previous experiments demonstrated precision scaling approaching Heisenberg-limited performances, reaching such a regime for a wide range of N remains hard to accomplish. Here, we show a method that suitably allocates the available resources permitting them to reach the same power law of Heisenberg scaling without any prior information on the parameter. We demonstrate experimentally such an advantage in measuring a rotation angle. We quantitatively verify sub-standard quantum limit performances for a considerable range of N (O(30,000)) by using single-photon states with high-order orbital angular momentum, achieving an error reduction, in terms of the obtained variance, >10 dB below the standard quantum limit. Such results can be applied to different scenarios, opening the way to the optimization of resources in quantum sensing.

arXiv:2110.02908•npj Quantum Information•Mar 2, 2023•18 citations

Joint Estimation of a Two-Phase Spin Rotation beyond Classical Limit

Jiahao Cao, Xinwei Li, Tian-Wei Mao +2 more

Quantum metrology employs entanglement to enhance measurement precision [V. Giovannetti et al., Quantum-enhanced measurements: Beating the standard quantum limit, Science 306, 1330 (2004)SCIEAS0036-807510.1126/science.1104149, V. Giovannetti et al., Advances in quantum metrology, Nat. Photonics 5, 222 (2011)NPAHBY1749-488510.1038/nphoton.2011.35, and L. Pezzè et al., Quantum metrology with nonclassical states of atomic ensembles, Rev. Mod. Phys. 90, 035005 (2018)RMPHAT0034-686110.1103/RevModPhys.90.035005]. The focus and progress so far have primarily centered on estimating a single parameter. In diverse application scenarios, estimation of more than one single parameter is often required. Joint estimation of multiple parameters can benefit from additional advantages for further enhanced precision. Here we report quantum-enhanced estimation of simultaneous spin rotations around two orthogonal axes, making use of spin-nematic squeezing in an atomic Bose-Einstein condensate. Aided by the F=2 atomic ground hyperfine manifold coupled to the nematic-squeezed F=1 states as an auxiliary field through a sequence of microwave (MW) pulses, multiple spin-1 observables are simultaneously measured, reaching an enhancement factor 3.3 to 6.3 decibels (dB) beyond the classical limit over a wide range of rotation angles. Our work realizes the first quantum enhanced multiparameter estimation using entangled massive particles. The techniques developed and the protocols implemented also highlight the application of two-mode squeezed vacuum states in quantum-enhanced sensing of noncommuting spin rotations simultaneously.

arXiv:2312.10480•Physical Review Letters•Jun 16, 2025•4 citations

Quantum Information Techniques for Quantum Metrology

Nathan Shettell

Quantum metrology is an auspicious discipline of quantum information which is currently witnessing a surge of experimental breakthroughs and theoretical developments. The main goal of quantum metrology is to estimate unknown parameters as accurately as possible. By using quantum resources as probes, it is possible to attain a measurement precision that would be otherwise impossible using the best classical strategies. For example, with respect to the task of phase estimation, the maximum precision (the Heisenberg limit) is a quadratic gain in precision with respect to the best classical strategies. Of course, quantum metrology is not the sole quantum technology currently undergoing advances. The theme of this thesis is exploring how quantum metrology can be enhanced with other quantum techniques when appropriate, namely: graph states, error correction and cryptography.

arXiv:2201.01523•Jan 5, 2022•1 citation

Experimental Advances in Phase Estimation with Photonic Quantum States

Laura T. Knoll, Agustina G. Magnoni, M. A. Larotonda

Photonic quantum metrology has emerged as a leading platform for quantum-enhanced precision measurements. By taking advantage of quantum resources such as entanglement, quantum metrology enables parameter estimation with sensitivities surpassing classical limits. In this review, we describe the basic tools and recent experimental progress in the determination of an optical phase with a precision that may exceed the shot-noise limit, enabled by the use of nonclassical states of light. We review the state of the art and discuss the challenges and trends in the field.

Entropy•Jul 1, 2025•2 citations
Quantum metrology allows for a tremendous boost in the accuracy of measurement of diverse physical parameters. The estimation of a rotation constitutes a remarkable example of this quantum-enhanced precision. The recently introduced Kings of Quantumness are especially germane for this task when the rotation axis is unknown, as they have a sensitivity independent of that axis and they achieve a Heisenberg-limit scaling. Here, we report the experimental realization of these states by generating up to 21-dimensional orbital angular momentum states of single photons, and confirm their high metrological abilities. (C) 2017 Optical Society of America.
Quantum metrology allows for a tremendous boost in the accuracy of measurement of diverse physical parameters. The estimation of a rotation constitutes a remarkable example of this quantum-enhanced precision. The recently introduced Kings of Quantumness are especially germane for this task when the rotation axis is unknown, as they have a sensitivity independent of that axis and they achieve a Heisenberg-limit scaling. Here, we report the experimental realization of these states by generating up to 21-dimensional orbital angular momentum states of single photons, and confirm their high metrological abilities.
Abstract Even the most classical states are still governed by quantum theory. A number of physical systems can be described by their Majorana constellations of points on the surface of a sphere, where concentrated constellations and highly symmetric distributions correspond to the least and most quantum states, respectively. If these points are chosen randomly, how quantum will the resultant state be, on average? We explore this simple conceptual question in detail, investigating the quantum properties of the resulting random states. We find these states to be far from the norm, even in the large-number-of-particles limit, where classical intuition often replaces quantum properties, making random Majorana constellations peculiar and intriguing. Moreover, we study their usefulness in the context of rotation sensing and find numerical evidence of their robustness against dephasing and particle loss. We realize these states experimentally using light’s orbital angular momentum degree of freedom and implement arbitrary unitaries with a multiplane light conversion setup to demonstrate the rotation sensing. Our findings open up new possibilities for quantum-enhanced metrology.
Abstract Adopting quantum resources for parameter estimation discloses the possibility to realize quantum sensors operating at a sensitivity beyond the standard quantum limit. Such an approach promises to reach the fundamental Heisenberg scaling as a function of the employed resources N in the estimation process. Although previous experiments demonstrated precision scaling approaching Heisenberg-limited performances, reaching such a regime for a wide range of N remains hard to accomplish. Here, we show a method that suitably allocates the available resources permitting them to reach the same power law of Heisenberg scaling without any prior information on the parameter. We demonstrate experimentally such an advantage in measuring a rotation angle. We quantitatively verify sub-standard quantum limit performances for a considerable range of N (O(30,000)) by using single-photon states with high-order orbital angular momentum, achieving an error reduction, in terms of the obtained variance, >10 dB below the standard quantum limit. Such results can be applied to different scenarios, opening the way to the optimization of resources in quantum sensing.
Quantum metrology employs entanglement to enhance measurement precision [V. Giovannetti et al., Quantum-enhanced measurements: Beating the standard quantum limit, Science 306, 1330 (2004)SCIEAS0036-807510.1126/science.1104149, V. Giovannetti et al., Advances in quantum metrology, Nat. Photonics 5, 222 (2011)NPAHBY1749-488510.1038/nphoton.2011.35, and L. Pezzè et al., Quantum metrology with nonclassical states of atomic ensembles, Rev. Mod. Phys. 90, 035005 (2018)RMPHAT0034-686110.1103/RevModPhys.90.035005]. The focus and progress so far have primarily centered on estimating a single parameter. In diverse application scenarios, estimation of more than one single parameter is often required. Joint estimation of multiple parameters can benefit from additional advantages for further enhanced precision. Here we report quantum-enhanced estimation of simultaneous spin rotations around two orthogonal axes, making use of spin-nematic squeezing in an atomic Bose-Einstein condensate. Aided by the F=2 atomic ground hyperfine manifold coupled to the nematic-squeezed F=1 states as an auxiliary field through a sequence of microwave (MW) pulses, multiple spin-1 observables are simultaneously measured, reaching an enhancement factor 3.3 to 6.3 decibels (dB) beyond the classical limit over a wide range of rotation angles. Our work realizes the first quantum enhanced multiparameter estimation using entangled massive particles. The techniques developed and the protocols implemented also highlight the application of two-mode squeezed vacuum states in quantum-enhanced sensing of noncommuting spin rotations simultaneously.
Quantum metrology is an auspicious discipline of quantum information which is currently witnessing a surge of experimental breakthroughs and theoretical developments. The main goal of quantum metrology is to estimate unknown parameters as accurately as possible. By using quantum resources as probes, it is possible to attain a measurement precision that would be otherwise impossible using the best classical strategies. For example, with respect to the task of phase estimation, the maximum precision (the Heisenberg limit) is a quadratic gain in precision with respect to the best classical strategies. Of course, quantum metrology is not the sole quantum technology currently undergoing advances. The theme of this thesis is exploring how quantum metrology can be enhanced with other quantum techniques when appropriate, namely: graph states, error correction and cryptography.
Photonic quantum metrology has emerged as a leading platform for quantum-enhanced precision measurements. By taking advantage of quantum resources such as entanglement, quantum metrology enables parameter estimation with sensitivities surpassing classical limits. In this review, we describe the basic tools and recent experimental progress in the determination of an optical phase with a precision that may exceed the shot-noise limit, enabled by the use of nonclassical states of light. We review the state of the art and discuss the challenges and trends in the field.