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

Journal of Applied Physics

Copper ion concentration detection based on quantum weak measurement of circular dichroism

Tingting Tang, Hua Wei Huang, Jun Li, Yu He, Jie Li, Xiao Liang, Chaoyang Li

Published Mar 25, 2024• 0 citations
Publisher

Abstract

In this paper, a high precision detection method of copper ion (Cu2+) concentration based on weak measurement is proposed. The ternary complex formed by Cu2+ with L-tryptophan and phenanthroline reagents has circular dichroism (CD) signal at 605 nm in visible light. The CD signal can be obtained using the intensity contrast as a pointer in the imaginary weak-value amplification scheme. The measured sensitivity and resolution are 0.3417 mradl/mg and 0.058 mg/l, respectively, which is improved by an order of magnitude compared to the traditional CD measurement method. It is also more accurate and less costly than commonly used Cu2+ detection methods. The Cu2+ concentration detection based on the weak measurement of CD signal detection proposed in this paper not only brings technological breakthroughs in the field of heavy metal ion detection, but also is of great significance in promoting the cross-development of chemistry, biomedicine, and life sciences.

DOI
10.1063/5.0192743

Related papers

Precise measurement of chiral spectrum in the ultraviolet band using weak measurement and a deep neural network model

Tingting Tang, Ying Gao, Yu He +7 more

Circular dichroism (CD) spectrum and optical rotation (OR) spectrum, crucial for understanding molecular properties and configurations, present challenges due to limited testing methods and equipment accuracy in the ultraviolet (UV) region. This study proposes a weak measurement system for chiral signals in varying concentrations in the ultraviolet range, optimized using a deep neural network (DNN) model. Introducing different post-selections to detect the circular dichroism spectrum and optical rotation spectrum separately, with contrast as a probe, it achieves a detection resolution of up to 10 −6 rad. Moreover, the fitted value of the training data can reach 0.9989, enhancing the prediction accuracy of chiral molecule concentrations. This method exhibits considerable promise for applications in chiral measurement and sensor technologies.

Optics Letters•Jul 8, 2024•4 citations

High-Precise Measurement of Optical Rotatory Dispersion Based on Weak Value Amplification

Jingyi Shao, Lan E Luo, Yu He +4 more

Chiroptical signals (generally very weak) play significant roles in chiral discrimination that bring great benefits in biochemistry, pharmacy, chemical, and so on. But, high-precise chiroptical detection is still a challenge. In this paper, a high-precise measurement of optical rotatory dispersion (ORD) based on weak value amplification (WVA) is presented. We proposed ORD detection method with parameter separation: by introducing complex coupling strength and dimensionless parameter “intensitiy contrast ratio” pointer, the ORD is only associated with the imaginary part of the weak value while circular dichroism (CD) is only associated with the real part. By designing a suitable WVA scheme, the ORD and CD can be measured separately. In the experiment, the reliability of the parameter separation method for ORD measurement is verified, and the precision reach the order of $10^{-6}$ rad. This method has a broad application prospect in biomedical sensing, medicine, chemical analysis and other fields.

IEEE photonics journal•Jul 7, 2021•15 citations

Optimal circular dichroism sensing with quantum light: Multiparameter estimation approach

Christina Ioannou, Ranjith Nair, Ivan Fernandez‐Corbaton +3 more

The measurement of circular dichroism (CD) has widely been exploited to distinguish the different enantiomers of chiral structures. It has been applied to natural materials (e.g., molecules) as well as to artificial materials (e.g., nanophotonic structures). However, especially for chiral molecules the signal level is very low and increasing the signal-to-noise ratio is of paramount importance to either shorten the necessary measurement time or to lower the minimum detectable molecule concentration. As one solution to this problem, we propose here to use quantum states of light in CD sensing to reduce the noise below the shot noise level encountered when using coherent states of light. Through a multiparameter estimation approach, we identify the ultimate quantum limit of the precision in CD sensing, allowing for general schemes including additional ancillary modes. We show that the ultimate quantum limit can be achieved by various optimal schemes. These include using a pair of Fock-state probes in a direct sensing configuration and pairs of twin beams in an ancilla-assisted sensing configuration, for both of which photon number-resolved detection is shown to be the optimal measurement. These optimal schemes offer a significant quantum enhancement even in the presence of some additional system loss. The near optimality of a scheme using a single twin beam in a direct sensing configuration is also shown for cases where the actual CD signal is very small. Alternative optimal schemes involving single-photon sources and detectors are also proposed. This work paves the way for further investigations of quantum metrological techniques in chirality sensing.

arXiv:2008.03888•Physical Review A•Nov 22, 2021•16 citations

Quantum weak measurement amplifies dispersion signal of Rydberg atomic system

Yinghang Jiang, Jiguo Wu, Meng Shi +4 more

This paper presents a scheme to amplify dispersion signal of Rydberg atomic microwave detection system, using a quantum weak measurement technique together with improved dimensionless pointer. The scheme effectively mitigates the impact of technical noise and can be used to achieve a measurement precision close to the limit set by atomic shot noise in theory. Compared with the superheterodyne method based on transmission detection, our scheme has been experimentally proved to have a sensitivity increase of 5 ~ 6 dB. In this work, the Rydberg dispersion signal amplification mechanism offers an approach to enhance microwave detection sensitivity, which also facilitates deeper investigations into its dynamic processes and further applications of this mechanism in quantum communication and quantum control. The authors propose a weak value measurement scheme to amplify the dispersion signal of Rydberg atom-based microwave electric field sensors using a superheterodyne technique. Experimentally, they demonstrate that this scheme improves the sensitivity of the microwave receiver by ~ 5-6dB compared to traditional amplitude-based superheterodyne detection.

arXiv:2503.03085•Communications Physics•Apr 9, 2025•7 citations

Realization of ultra-small stress birefringence detection with weak-value amplification technique

Yongsheng Wang, Shizhen Chen, Shuangchun Wen +1 more

How to realize the detection of tiny birefringence is an important but challenging issue for investigations and applications in optics. In weak measurements, weak-value amplification has been widely applied to the precise estimation of time delay. Here, we show that the linear amplification in weak measurements has the potential to outperform standard weak-value amplification for ultra-small parameter characterization. The higher measurement accuracy in the linear amplification enables us to achieve a measurement of stress-induced birefringence with a high resolution of 5×10−10. Compared with existing methods, the accuracy based on weak measurements for birefringence detection can improve two orders of magnitude. Our method may have important applications in a variety of fields involving the precise measurement of time delay or birefringence.

Applied Physics Letters•Apr 19, 2021•20 citations

High-Throughput Chiral Molecule Determination Based on Multi-Channel Weak Measurement

Lixuan Shi, Yang Xu, Zhen Qiao +7 more

A multi-channel high-throughput chiral molecule determination method based on weak value amplification (WVA) is proposed for the first time. This method can be used for high-throughput and high-precision determination of chiral molecule. Through the design of multi-channel weak measurement system, we realized the real-time, high-throughput, high-sensitivity and high-resolution detection of chiral molecules by selecting proper measurement states. In this work, we have realized a sensitivity of 11.8 nm/° and a resolution of 3.13 × 10-4° for measuring optical rotation. Moreover, the proposed method is successfully applied for detection of lactose content in milk samples. Furthermore, the system has the advantages of simple and robust real-time detection settings, strong stability, high measurement efficiency and good scalability. This method has important significance in clinical diagnosis, food safety and biological system.

IEEE photonics journal•Apr 6, 2021•2 citations
In this paper, a high precision detection method of copper ion (Cu2+) concentration based on weak measurement is proposed. The ternary complex formed by Cu2+ with L-tryptophan and phenanthroline reagents has circular dichroism (CD) signal at 605 nm in visible light. The CD signal can be obtained using the intensity contrast as a pointer in the imaginary weak-value amplification scheme. The measured sensitivity and resolution are 0.3417 mradl/mg and 0.058 mg/l, respectively, which is improved by an order of magnitude compared to the traditional CD measurement method. It is also more accurate and less costly than commonly used Cu2+ detection methods. The Cu2+ concentration detection based on the weak measurement of CD signal detection proposed in this paper not only brings technological breakthroughs in the field of heavy metal ion detection, but also is of great significance in promoting the cross-development of chemistry, biomedicine, and life sciences.
Circular dichroism (CD) spectrum and optical rotation (OR) spectrum, crucial for understanding molecular properties and configurations, present challenges due to limited testing methods and equipment accuracy in the ultraviolet (UV) region. This study proposes a weak measurement system for chiral signals in varying concentrations in the ultraviolet range, optimized using a deep neural network (DNN) model. Introducing different post-selections to detect the circular dichroism spectrum and optical rotation spectrum separately, with contrast as a probe, it achieves a detection resolution of up to 10 −6 rad. Moreover, the fitted value of the training data can reach 0.9989, enhancing the prediction accuracy of chiral molecule concentrations. This method exhibits considerable promise for applications in chiral measurement and sensor technologies.
Chiroptical signals (generally very weak) play significant roles in chiral discrimination that bring great benefits in biochemistry, pharmacy, chemical, and so on. But, high-precise chiroptical detection is still a challenge. In this paper, a high-precise measurement of optical rotatory dispersion (ORD) based on weak value amplification (WVA) is presented. We proposed ORD detection method with parameter separation: by introducing complex coupling strength and dimensionless parameter “intensitiy contrast ratio” pointer, the ORD is only associated with the imaginary part of the weak value while circular dichroism (CD) is only associated with the real part. By designing a suitable WVA scheme, the ORD and CD can be measured separately. In the experiment, the reliability of the parameter separation method for ORD measurement is verified, and the precision reach the order of 10−610^{-6}10−6 rad. This method has a broad application prospect in biomedical sensing, medicine, chemical analysis and other fields.
The measurement of circular dichroism (CD) has widely been exploited to distinguish the different enantiomers of chiral structures. It has been applied to natural materials (e.g., molecules) as well as to artificial materials (e.g., nanophotonic structures). However, especially for chiral molecules the signal level is very low and increasing the signal-to-noise ratio is of paramount importance to either shorten the necessary measurement time or to lower the minimum detectable molecule concentration. As one solution to this problem, we propose here to use quantum states of light in CD sensing to reduce the noise below the shot noise level encountered when using coherent states of light. Through a multiparameter estimation approach, we identify the ultimate quantum limit of the precision in CD sensing, allowing for general schemes including additional ancillary modes. We show that the ultimate quantum limit can be achieved by various optimal schemes. These include using a pair of Fock-state probes in a direct sensing configuration and pairs of twin beams in an ancilla-assisted sensing configuration, for both of which photon number-resolved detection is shown to be the optimal measurement. These optimal schemes offer a significant quantum enhancement even in the presence of some additional system loss. The near optimality of a scheme using a single twin beam in a direct sensing configuration is also shown for cases where the actual CD signal is very small. Alternative optimal schemes involving single-photon sources and detectors are also proposed. This work paves the way for further investigations of quantum metrological techniques in chirality sensing.
This paper presents a scheme to amplify dispersion signal of Rydberg atomic microwave detection system, using a quantum weak measurement technique together with improved dimensionless pointer. The scheme effectively mitigates the impact of technical noise and can be used to achieve a measurement precision close to the limit set by atomic shot noise in theory. Compared with the superheterodyne method based on transmission detection, our scheme has been experimentally proved to have a sensitivity increase of 5 ~ 6 dB. In this work, the Rydberg dispersion signal amplification mechanism offers an approach to enhance microwave detection sensitivity, which also facilitates deeper investigations into its dynamic processes and further applications of this mechanism in quantum communication and quantum control. The authors propose a weak value measurement scheme to amplify the dispersion signal of Rydberg atom-based microwave electric field sensors using a superheterodyne technique. Experimentally, they demonstrate that this scheme improves the sensitivity of the microwave receiver by ~ 5-6dB compared to traditional amplitude-based superheterodyne detection.
How to realize the detection of tiny birefringence is an important but challenging issue for investigations and applications in optics. In weak measurements, weak-value amplification has been widely applied to the precise estimation of time delay. Here, we show that the linear amplification in weak measurements has the potential to outperform standard weak-value amplification for ultra-small parameter characterization. The higher measurement accuracy in the linear amplification enables us to achieve a measurement of stress-induced birefringence with a high resolution of 5×10−10. Compared with existing methods, the accuracy based on weak measurements for birefringence detection can improve two orders of magnitude. Our method may have important applications in a variety of fields involving the precise measurement of time delay or birefringence.
A multi-channel high-throughput chiral molecule determination method based on weak value amplification (WVA) is proposed for the first time. This method can be used for high-throughput and high-precision determination of chiral molecule. Through the design of multi-channel weak measurement system, we realized the real-time, high-throughput, high-sensitivity and high-resolution detection of chiral molecules by selecting proper measurement states. In this work, we have realized a sensitivity of 11.8 nm/° and a resolution of 3.13 × 10-4° for measuring optical rotation. Moreover, the proposed method is successfully applied for detection of lactose content in milk samples. Furthermore, the system has the advantages of simple and robust real-time detection settings, strong stability, high measurement efficiency and good scalability. This method has important significance in clinical diagnosis, food safety and biological system.