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An Improved Quantum Projection Filter [article]

Qing Gao and Guofeng Zhang and Ian R. Petersen
2019 arXiv   pre-print
This work extends the previous quantum projection filtering scheme in [Gao Q., Zhang G., Petersen I. R. (2019). An exponential quantum projection filter for open quantum systems.  ...  Simulation results for a qubit example demonstrate better approximation performance for the new quantum projection filter.  ...  Given the geometric structure of S, one can obtain an explicit form for the quantum projection filter using Theorem 4.1.  ... 
arXiv:1909.13524v1 fatcat:ihfn664jlvco7jnhr7xvh3vpwu

Modern UV detectors for small aperture space mission to study comets

A. Shugarov
2021 Contributions of the Astronomical Observatory Skalnaté Pleso  
The improvements of classical CCD are moving toward improving quantum efficiency in UV, development of the new anti-reflection coatings and multilayer UV filters with enhanced red leak suppression.  ...  We discuss the latest trends in UV-optimized CMOS and CCD detectors that can improve the efficiency of a small aperture (20 cm) space burn UV telescope.  ...  In the DORADO project it is proposed to use a multilayer dielectric filter on the CCD surface Singer et al. (2021) .  ... 
doi:10.31577/caosp.2021.51.3.257 fatcat:oar3snenhbfc3podbjutzppa6q

Magnetometry via a double-pass continuous quantum measurement of atomic spin

Bradley A. Chase, Ben Q. Baragiola, Heather L. Partner, Brigette D. Black, J. M. Geremia
2009 Physical Review A. Atomic, Molecular, and Optical Physics  
Using the methods of quantum stochastic calculus and filtering theory, we demonstrate numerically an explicit parameter estimator (called a quantum particle filter) whose observed scaling follows that  ...  Moreover, the quantum particle filter quantitatively surpasses the uncertainty limit calculated from the quantum Cramer-Rao inequality based on a magnetic coupling Hamiltonian with only single-body operators  ...  SIMULATIONS Given the absence of an analytic improvement in the sensitivity of the quantum Kalman filter, we turn to numerical simulations of the quantum particle filter in order to gauge the potential  ... 
doi:10.1103/physreva.79.062107 fatcat:wyz577hjafd3vdlg7lzkzsliby

Electronic Nose Technology Based on Quantum Dot Filters

Zhenan Li, Jie Bao
2017 Optics and Photonics Journal  
This paper demonstrates using quantum dot spectroscopy technology to solve this problem. Multiple quantum dot filters are placed on the surface of image sensor.  ...  Simulation and experiment both prove that quantum dot filters with appropriate processing are more sensitive to color changes than RGB filters.  ...  It is feasible to design band-pass base with quantum dot for improving the performance. Quantum Dot Processing Quantum dot filters are used to fit band-pass filter.  ... 
doi:10.4236/opj.2017.78b005 fatcat:yao5glj3kngp7m4sece6vbbsfm

Quantum Kalman Filtering and the Heisenberg Limit in Atomic Magnetometry

JM Geremia, John K. Stockton, Andrew C. Doherty, Hideo Mabuchi
2003 Physical Review Letters  
We show that continuous measurement coupled with quantum Kalman filtering provides an optimal procedure for magnetic detection limits that scale with 1/N, the Heisenberg squeezing limit.  ...  The shot-noise detection limit in current high-precision atomic magnetometry is a manifestation of quantum fluctuations that scale as the square root of N in an ensemble of N particles.  ...  intrinsic limit on the field sensitivity, reducing the projection noise below its standard quantum limit would improve the precision.  ... 
doi:10.1103/physrevlett.91.250801 pmid:14754102 fatcat:6lzf4wwrgbgnlie4u6mm5oc2za

Efficient state initialization by a quantum spectral filtering algorithm

François Fillion-Gourdeau, Steve MacLean, Raymond Laflamme
2017 Physical Review A  
This is performed by introducing a nondeterministic quantum implementation of a standard spectral filtering procedure combined with an apodization technique, allowing for accurate state initialization.  ...  An algorithm that initializes a quantum register to a state with a specified energy range is given, corresponding to a quantum implementation of the celebrated Feit-Fleck method.  ...  Therefore, our quantum filtering technique is an interesting alternative from this standpoint. VI.  ... 
doi:10.1103/physreva.95.042331 fatcat:uqoarfopqbey7ndymy67b25ppm

Amplified Quantum Dynamics and Enhanced Parameter Sensitivity via Coherent Feedback in Collective Atomic Spin Systems [article]

Bradley A. Chase, JM Geremia
2009 arXiv   pre-print
Combining the nonlinear dynamics that result from the positive feedback with continuous observation of the atomic spin offers an improvement in quantum parameter estimation.  ...  An effective equation of motion for the atomic system is presented, and an approximate 2-parameter model of the dynamics is developed that should provide a viable approach to modeling even the extremely  ...  With the Gaussian family of states defined, an approximate quantum filtering equation confined to the family can be derived. Our approach utilizes the technique of projection filtering [42, 17] .  ... 
arXiv:0905.0931v1 fatcat:wbinekfttngfhpsubulwixccgq

Error mitigation for variational quantum algorithms through mid-circuit measurements [article]

Ludmila Botelho, Adam Glos, Akash Kundu, Jarosław Adam Miszczak, Özlem Salehi, Zoltán Zimborás
2021 arXiv   pre-print
With this pre-knowledge, some errors can be detected in the course of the evolution of the circuit, by filtering the states not obeying the pattern through post-selection.  ...  For the particular subspace of one-hot states, we propose a method that works by compressing the full Hilbert space to a smaller subspace, allowing projecting to the desired subspace without using any  ...  The effect of the post-selection discussed above can be improved by performing post-selection in the middle of the circuit by projection onto the subspace P 2 , as the valid states belong to the subspace  ... 
arXiv:2108.10927v2 fatcat:f4ff4ttrtrhpbcuz2f6lz3sifa

Task-based assessment of breast tomosynthesis: Effect of acquisition parameters and quantum noisea)

I. Reiser, R. M. Nishikawa
2010 Medical Physics (Lancaster)  
Tomosynthesis scan angle had an effect on detectability for all signals sizes, while quantum noise and angular sampling only affected the detectability small-scale signals.  ...  Detectability in tomosynthesis was compared to that in a single projection.  ...  ACKNOWLEDGMENTS The authors would like to thank Art Burgess for helpful discussions on model observers and filtered noise backgrounds. This work was funded in part by NCI Grant Nos.  ... 
doi:10.1118/1.3357288 pmid:20443480 pmcid:PMC2852443 fatcat:4dx3fj37lfaxriajxwxxfwblpq

In Vivo Triple Quantum Filtered Twisted Projection Sodium MRI of Human Articular Cartilage

Arijitt Borthakur, Ileana Hancu, Fernando E. Boada, Gary X. Shen, Erik M. Shapiro, Ravinder Reddy
1999 Journal of magnetic resonance (San Diego, Calif. 1997 : Print)  
In this work, we present the first triple quantum filtered (TQF) sodium MR images of the human knee joint in vivo.  ...  Images clearly demarcate patellar cartilage and also demonstrate fluid signal suppressed by the triple quantum filter.  ...  ACKNOWLEDGMENTS This work was performed with the help of an NIH-supported resource center (NIH RR02305), NIH Grants RO1-AR45242 and RO1-AR45404, and the Whitaker Foundation.  ... 
doi:10.1006/jmre.1999.1923 pmid:10579951 fatcat:3xsychx5nnfjbfozw5tqc7ufga

Quantum projection filter for a highly nonlinear model in cavity QED

Ramon van Handel, Hideo Mabuchi
2005 Journal of Optics B-Quantum and Semiclassical Optics  
We observe near-optimal performance of the quantum projection filter, demonstrating the utility of such an approach.  ...  One solution proposed in classical filtering theory is that of the projection filter.  ...  Thus even the Q-function projection filter is a true quantum projection filter, as long as we project onto a family of Q-functions that correspond to valid quantum states.  ... 
doi:10.1088/1464-4266/7/10/005 fatcat:qywof6t6yvhghen4ui2t7tybdm

Smart City Moving Target Tracking Algorithm Based on Quantum Genetic and Particle Filter

Zhigang Liu, Jin Shang, Xufen Hua
2020 Wireless Communications and Mobile Computing  
In this paper, a particle filter algorithm combined with quantum genetic algorithm (QGA) is proposed to solve the above problems.  ...  It can be seen that in nonlinear state, the quantum genetic and particle filter (QGPF) algorithm can achieve a higher accuracy of state estimation, and the filtering error of QGPF algorithm at each time  ...  Acknowledgments This research is supported by the "cyan and blue project" of Jiangsu Higher Education Institutions of China.  ... 
doi:10.1155/2020/8865298 fatcat:vqf23wwq6fe3fgujysmmttmyom

Optimal probabilistic measurement of phase

Petr Marek
2013 Physical Review A. Atomic, Molecular, and Optical Physics  
When measuring phase of quantum states of light, the optimal single-shot measurement implements projection on the un-physical phase states.  ...  If we want to improve the precision further we need to accept a reduced probability of success, either by implementing a probabilistic measurement or by probabilistically manipulating the measured quantum  ...  The work was supported by project P205/12/0577 of Grant Agency of Czech Republic.  ... 
doi:10.1103/physreva.88.045802 fatcat:jo3lduse35dutim4bf7ttcbcqe

Contrast enhancement methods in sodium MR imaging: a new emerging technique

Rakesh Sharma, Avdhesh Sharma, Soonjo Kwon, Ross Booth
2009 Journal of Biomedical Science and Engineering  
Contrast enhancement: We highlight the physical principles of sodium MRI in three different pulse sequences using filters (single quantum, multiple quantum, and triple quantum) meant for sodium contrast  ...  The optimized MRI scan parameters in quantum filter techniques generate contrast in intracellular sodium MR images without using invasive contrast shift agents.  ...  For double quantum filtered images, m=+2, and for triple quantum filtered images, m=+3.  ... 
doi:10.4236/jbise.2009.26065 fatcat:2gqm6snqzzg6na3owqzdsq4llm

Quantum optical frequency conversion for polarisation entangled qubits: towards interconnected quantum information devices [article]

Florian Kaiser and Panagiotis Vergyris and Anthony Martin and Djeylan Aktas and Olivier Alibart and Sébastien Tanzilli
2019 arXiv   pre-print
, at which a variety of quantum memories operate.  ...  Realising a global quantum network requires combining individual strengths of different quantum systems to perform universal tasks, notably using flying and stationary qubits.  ...  This work was conducted within the framework of the project OPTIMAL granted by the European Union by means of the Fond Européen de développement régional, FEDER. ADDITIONAL INFORMATION  ... 
arXiv:1901.09826v1 fatcat:slmmeu6ts5fyhk6fkxte4wzxwq
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