Pub Date : 2024-11-22DOI: 10.1038/s41534-024-00917-7
Jonathan A. Gross, Élie Genois, Dripto M. Debroy, Yaxing Zhang, Wojciech Mruczkiewicz, Ze-Pei Cian, Zhang Jiang
Repeating a gate sequence multiple times amplifies systematic errors coherently, making it a useful tool for characterizing quantum gates. However, the precision of such an approach is limited by low-frequency noise, while its efficiency is hindered by time-consuming scans required to match up the phases of the off-diagonal matrix elements being amplified. Here, we overcome both challenges by interleaving the gate of interest with dynamical decoupling sequences in a protocol we call Matrix-Element Amplification using Dynamical Decoupling (MEADD). Using frequency-tunable superconducting qubits from a Google Sycamore quantum processor, we experimentally demonstrate that MEADD surpasses the accuracy and precision of existing characterization protocols for estimating systematic errors in single- and two-qubit gates. We use MEADD to estimate coherent parameters of CZ gates with 5 to 10 times the precision of existing methods and to characterize previously undetectable coherent crosstalk, reaching a precision below one milliradian.
{"title":"Characterizing coherent errors using matrix-element amplification","authors":"Jonathan A. Gross, Élie Genois, Dripto M. Debroy, Yaxing Zhang, Wojciech Mruczkiewicz, Ze-Pei Cian, Zhang Jiang","doi":"10.1038/s41534-024-00917-7","DOIUrl":"https://doi.org/10.1038/s41534-024-00917-7","url":null,"abstract":"<p>Repeating a gate sequence multiple times amplifies systematic errors coherently, making it a useful tool for characterizing quantum gates. However, the precision of such an approach is limited by low-frequency noise, while its efficiency is hindered by time-consuming scans required to match up the phases of the off-diagonal matrix elements being amplified. Here, we overcome both challenges by interleaving the gate of interest with dynamical decoupling sequences in a protocol we call Matrix-Element Amplification using Dynamical Decoupling (MEADD). Using frequency-tunable superconducting qubits from a Google Sycamore quantum processor, we experimentally demonstrate that MEADD surpasses the accuracy and precision of existing characterization protocols for estimating systematic errors in single- and two-qubit gates. We use MEADD to estimate coherent parameters of CZ gates with 5 to 10 times the precision of existing methods and to characterize previously undetectable coherent crosstalk, reaching a precision below one milliradian.</p>","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"35 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optically controllable delivery of microparticles excites interesting research and applications in various fields because of the noninvasive and noncontact features. However, long-distance delivery with a static low-power light source remains challenging. Here, the constant-force photonic projectile (CFPP) is employed to achieve long-distance delivery of microparticles with a low-power laser beam. The CFPP takes advantage of photon absorption to create a constant optical force within a large range, surpassing traditional tweezers. The concept of CFPP has been experimentally corroborated by remote control over micrometer-sized absorptive particles (APs) using a simple tilted focused beam. At the laser focus, strong photon absorption results in a large constant optical force that ejects the APs along the optical axis. Furthermore, the additional thermal convection field, which attracts particles from a distance into the working range of the CFPP, is utilized to collect the unbound APs for reuse. Finally, we demonstrate the concept of drug delivery by transporting a small microparticle onto a host particle at a remote location. The proposed CFPP provides a new perspective for drug delivery and heat-enhanced photodynamic therapy.
{"title":"Constant-force photonic projectile for long-distance targeting delivery","authors":"Chun Meng, Yu-Xuan Ren, Fengya Lu, Panpan Yu, Jinhua Zhou, Min-Cheng Zhong","doi":"10.1515/nanoph-2024-0484","DOIUrl":"https://doi.org/10.1515/nanoph-2024-0484","url":null,"abstract":"Optically controllable delivery of microparticles excites interesting research and applications in various fields because of the noninvasive and noncontact features. However, long-distance delivery with a static low-power light source remains challenging. Here, the constant-force photonic projectile (CFPP) is employed to achieve long-distance delivery of microparticles with a low-power laser beam. The CFPP takes advantage of photon absorption to create a constant optical force within a large range, surpassing traditional tweezers. The concept of CFPP has been experimentally corroborated by remote control over micrometer-sized absorptive particles (APs) using a simple tilted focused beam. At the laser focus, strong photon absorption results in a large constant optical force that ejects the APs along the optical axis. Furthermore, the additional thermal convection field, which attracts particles from a distance into the working range of the CFPP, is utilized to collect the unbound APs for reuse. Finally, we demonstrate the concept of drug delivery by transporting a small microparticle onto a host particle at a remote location. The proposed CFPP provides a new perspective for drug delivery and heat-enhanced photodynamic therapy.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"15 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142690543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maxime Giteau, Lukas Conrads, Andreas Mathwieser, Robert Schmitt, Matthias Wuttig, Thomas Taubner, Georgia T. Papadakis
Tailoring of thermal radiation is critical for applications like daytime radiative cooling, thermophotovoltaic energy conversion, and gas sensing. Phase‐change materials (PCMs) offer an additional degree of freedom, enabling reconfigurable thermal emission by actively triggering phase transitions. In particular, In3SbTe2 (IST) features a unique non‐volatile phase transition in the infrared between an amorphous dielectric state and a crystalline metallic state. Although efficient and easily manufacturable alternatives to conventional infrared light sources will be highly desirable, achieving narrowband and diffuse emission using a simple, lithography‐free structure incorporating PCMs for dynamic functionalities has remained elusive. Here, a planar reconfigurable narrowband thermal emitter using an IST layer on top of a Salisbury screen is demonstrated. The design achieves high emissivity around the ambient thermal wavelength in the amorphous phase and low emissivity in the crystalline phase, featuring angle‐ and polarization‐independent behavior. Multiple patterns are optically written into the IST layer, demonstrating centimeter‐scale programmability as well as a resolution of 20 µm. This work paves the way toward reconfigurable and easily manufacturable devices, showing potential for applications in labeling and anticounterfeiting.
调整热辐射对于日间辐射冷却、热光电能量转换和气体传感等应用至关重要。相变材料（PCM）提供了额外的自由度，通过主动触发相变，实现了可重新配置的热辐射。特别是 In3SbTe2（IST），它在红外非晶介电态和结晶金属态之间具有独特的非挥发性相变。虽然高效且易于制造的传统红外光源替代品将非常受欢迎，但使用简单、无光刻工艺的结构实现窄带和漫射发射，并结合 PCM 实现动态功能，仍是一个难以实现的目标。本文展示了一种平面可重构窄带热发射器，它在索尔兹伯里屏上使用了 IST 层。该设计在非晶相中实现了环境热波长附近的高发射率，在晶相中实现了低发射率，具有与角度和偏振无关的特性。多个图案以光学方式写入 IST 层，展示了厘米级的可编程性和 20 微米的分辨率。这项工作为实现可重新配置和易于制造的设备铺平了道路，显示出在标签和防伪领域的应用潜力。
{"title":"Switchable Narrowband Diffuse Thermal Emission With an In3SbTe2‐Based Planar Structure","authors":"Maxime Giteau, Lukas Conrads, Andreas Mathwieser, Robert Schmitt, Matthias Wuttig, Thomas Taubner, Georgia T. Papadakis","doi":"10.1002/lpor.202401438","DOIUrl":"https://doi.org/10.1002/lpor.202401438","url":null,"abstract":"Tailoring of thermal radiation is critical for applications like daytime radiative cooling, thermophotovoltaic energy conversion, and gas sensing. Phase‐change materials (PCMs) offer an additional degree of freedom, enabling reconfigurable thermal emission by actively triggering phase transitions. In particular, In<jats:sub>3</jats:sub>SbTe<jats:sub>2</jats:sub> (IST) features a unique non‐volatile phase transition in the infrared between an amorphous dielectric state and a crystalline metallic state. Although efficient and easily manufacturable alternatives to conventional infrared light sources will be highly desirable, achieving narrowband and diffuse emission using a simple, lithography‐free structure incorporating PCMs for dynamic functionalities has remained elusive. Here, a planar reconfigurable narrowband thermal emitter using an IST layer on top of a Salisbury screen is demonstrated. The design achieves high emissivity around the ambient thermal wavelength in the amorphous phase and low emissivity in the crystalline phase, featuring angle‐ and polarization‐independent behavior. Multiple patterns are optically written into the IST layer, demonstrating centimeter‐scale programmability as well as a resolution of 20 µm. This work paves the way toward reconfigurable and easily manufacturable devices, showing potential for applications in labeling and anticounterfeiting.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"253 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent discovery of gravitational waves (GWs) has opened a new avenue for investigating the equation of state (EOS) of dense matter in compact stars, which is an outstanding problem in astronomy and nuclear physics. In the future, next-generation (XG) GW detectors will be constructed, deemed to provide a large number of high-precision observations. We investigate the potential of constraining the EOS of quark stars (QSs) with high-precision measurements of mass m and tidal deformability Λ from the XG GW observatories. We adopt the widely-used bag model for QSs, consisting of four microscopic parameters: the effective bag constant Beff, the perturbative quantum chromodynamics correction parameter a4, the strange quark mass ms, and the pairing energy gap Δ. With the help of hierarchical Bayesian inference, for the first time we are able to infer the EOS of QSs combining multiple GW observations. Using the top 25 loudest GW events in our simulation, we find that, the constraints on Beff and Δ are tightened by several times, while a4 and ms are still poorly constrained. We also study a simplified 2-dimensional (2-d) EOS model which was recently proposed in literature. The 2-d model is found to exhibit significant parameter-estimation biases as more GW events are analyzed, while the predicted m–Λ relation remains consistent with the full model.
{"title":"Vetting quark-star models with gravitational waves in the hierarchical Bayesian framework","authors":"Ziming Wang, Yong Gao, Dicong Liang, Junjie Zhao and Lijing Shao","doi":"10.1088/1475-7516/2024/11/038","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/038","url":null,"abstract":"The recent discovery of gravitational waves (GWs) has opened a new avenue for investigating the equation of state (EOS) of dense matter in compact stars, which is an outstanding problem in astronomy and nuclear physics. In the future, next-generation (XG) GW detectors will be constructed, deemed to provide a large number of high-precision observations. We investigate the potential of constraining the EOS of quark stars (QSs) with high-precision measurements of mass m and tidal deformability Λ from the XG GW observatories. We adopt the widely-used bag model for QSs, consisting of four microscopic parameters: the effective bag constant Beff, the perturbative quantum chromodynamics correction parameter a4, the strange quark mass ms, and the pairing energy gap Δ. With the help of hierarchical Bayesian inference, for the first time we are able to infer the EOS of QSs combining multiple GW observations. Using the top 25 loudest GW events in our simulation, we find that, the constraints on Beff and Δ are tightened by several times, while a4 and ms are still poorly constrained. We also study a simplified 2-dimensional (2-d) EOS model which was recently proposed in literature. The 2-d model is found to exhibit significant parameter-estimation biases as more GW events are analyzed, while the predicted m–Λ relation remains consistent with the full model.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"2 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1088/1475-7516/2024/11/037
Sangwoo Park, Arman Shafieloo, Satadru Bag, Mikhail Denissenya, Eric V. Linder and Adarsh Ranjan
Internal kinematics of galaxies, traced through the stellar rotation curve or two dimensional velocity map, carry important information on galactic structure and dark matter. With upcoming surveys, the velocity map may play a key role in the development of kinematic lensing as an astrophysical probe. We improve techniques for extracting velocity information from integral field spectroscopy at low signal-to-noise (S/N), without a template, and demonstrate substantial advantages over the standard Penalized PiXel-Fitting method (pPXF) approach. Robust rotation curves can be derived down to S/N ≈ 2 using our method.
{"title":"Model independent approach for calculating galaxy rotation curves for low S/N MaNGA galaxies","authors":"Sangwoo Park, Arman Shafieloo, Satadru Bag, Mikhail Denissenya, Eric V. Linder and Adarsh Ranjan","doi":"10.1088/1475-7516/2024/11/037","DOIUrl":"https://doi.org/10.1088/1475-7516/2024/11/037","url":null,"abstract":"Internal kinematics of galaxies, traced through the stellar rotation curve or two dimensional velocity map, carry important information on galactic structure and dark matter. With upcoming surveys, the velocity map may play a key role in the development of kinematic lensing as an astrophysical probe. We improve techniques for extracting velocity information from integral field spectroscopy at low signal-to-noise (S/N), without a template, and demonstrate substantial advantages over the standard Penalized PiXel-Fitting method (pPXF) approach. Robust rotation curves can be derived down to S/N ≈ 2 using our method.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":"23 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tiancheng Zhao, Yuan Xu, Jiacheng Liu, Xiang Bao, Liu Yuan, Deen Gu
Temperature serves as a pivotal factor influencing information transmission and computational capacity in neurons, significantly affecting the function and efficiency of neural networks. However, the temperature dependence of VO2-based artificial neuron, which is one of the highly promising artificial neurons, has been hardly reported to date. Here, high-performance VO2 devices with NDR features are prepared by rapid annealing and electroforming processes. We constructed VO2-based artificial neurons with output properties similar to those of biological neurons on the basis of the Pearson–Anson oscillation circuit. The temperature-dependent behavior of VO2 neurons was fully investigated. Increasing temperature leads to a decrease in the peak-to-peak value of the output spikes of VO2 neurons. The spike period of VO2 neurons remains relatively stable near room temperature, but it decreases as the temperature reaches above 26 °C. These temperature-dependent features of VO2 neurons are similar to the ones of biological neurons, suggesting a natural advantage of VO2-based artificial neurons in mimicking biological neural activity. These findings contribute toward comprehending and regulating the temperature-dependent behavior of artificial neurons based on Mott memristor.
{"title":"Temperature-dependent behavior of VO2-based artificial neurons","authors":"Tiancheng Zhao, Yuan Xu, Jiacheng Liu, Xiang Bao, Liu Yuan, Deen Gu","doi":"10.1063/5.0231840","DOIUrl":"https://doi.org/10.1063/5.0231840","url":null,"abstract":"Temperature serves as a pivotal factor influencing information transmission and computational capacity in neurons, significantly affecting the function and efficiency of neural networks. However, the temperature dependence of VO2-based artificial neuron, which is one of the highly promising artificial neurons, has been hardly reported to date. Here, high-performance VO2 devices with NDR features are prepared by rapid annealing and electroforming processes. We constructed VO2-based artificial neurons with output properties similar to those of biological neurons on the basis of the Pearson–Anson oscillation circuit. The temperature-dependent behavior of VO2 neurons was fully investigated. Increasing temperature leads to a decrease in the peak-to-peak value of the output spikes of VO2 neurons. The spike period of VO2 neurons remains relatively stable near room temperature, but it decreases as the temperature reaches above 26 °C. These temperature-dependent features of VO2 neurons are similar to the ones of biological neurons, suggesting a natural advantage of VO2-based artificial neurons in mimicking biological neural activity. These findings contribute toward comprehending and regulating the temperature-dependent behavior of artificial neurons based on Mott memristor.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"34 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142690619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Manipulating photons in quantum photonic integrated circuits (QPICs) is essential for quantum communications and computation, demanding precise control over phase shifts and photon coupling. Despite the challenges arising from the low electro-optic and thermo-optic coefficients of glass waveguides, femtosecond laser direct writing (FsLDW) technology offers a rapid method for QPIC preparation. In this work, the use of auxiliary fields is proposed to reconfigure QPICs with FsLDW. Through adiabatic elimination, modulations of inter-waveguide coupling are achieved, allowing for arbitrary, controllable beam-splitting ratios and error correction in discrete quantum walking networks. The experiments also demonstrate full-period phase shift modulation over 2π in a Mach-Zehnder interferometer by employing an adjustable auxiliary field. Particularly, high-quality two-photon quantum interference and high-fidelity quantum logic function conversion between a controlled-NOT gate and a controlled-PHASE gate are exhibited. This novel approach provides a promising mechanism for modulating the phase and coupling between photons in 3D and large-scale QPICs.
{"title":"Reconfiguration of Quantum Photonic Integrated Circuits Using Auxiliary Fields","authors":"Ying-De Wang, Yang Chen, Zhi-Yong Hu, Yi-Ke Sun, Zhi-Yuan Zhang, Qi-Dai Chen, Guang-Can Guo, Zhen-Nan Tian, Xi-Feng Ren","doi":"10.1002/lpor.202401023","DOIUrl":"https://doi.org/10.1002/lpor.202401023","url":null,"abstract":"Manipulating photons in quantum photonic integrated circuits (QPICs) is essential for quantum communications and computation, demanding precise control over phase shifts and photon coupling. Despite the challenges arising from the low electro-optic and thermo-optic coefficients of glass waveguides, femtosecond laser direct writing (FsLDW) technology offers a rapid method for QPIC preparation. In this work, the use of auxiliary fields is proposed to reconfigure QPICs with FsLDW. Through adiabatic elimination, modulations of inter-waveguide coupling are achieved, allowing for arbitrary, controllable beam-splitting ratios and error correction in discrete quantum walking networks. The experiments also demonstrate full-period phase shift modulation over 2π in a Mach-Zehnder interferometer by employing an adjustable auxiliary field. Particularly, high-quality two-photon quantum interference and high-fidelity quantum logic function conversion between a controlled-NOT gate and a controlled-PHASE gate are exhibited. This novel approach provides a promising mechanism for modulating the phase and coupling between photons in 3D and large-scale QPICs.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"4 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1088/2058-9565/ad92a4
Yong Wang, Lijun Liu, Tong Dou, Li Li and Shuming Cheng
Quantum state tomography is a cornerstone of quantum information technologies to characterize and benchmark quantum systems from measurement statistics. In this work, we present an infidelity-based least-squares estimator, which incorporates the state purity information and provides orders of magnitude higher tomography accuracy than previous ones. It is further enhanced with the randomized toolbox of direct fidelity estimation, making it applicable to large-scale quantum systems. We validate the proposed estimators through extensive experiments conducted on the IBM Qiskit simulator. The results also demonstrate that our estimator admits an infidelity scaling with Pauli sample size N for (nearly) pure states. Further, it enables high-precision pure-state tomography for systems of up to 25-qubit states, given some state priors. Our method provides a novel perspective on the union of underlying tomography technique and state properties estimation.
量子态层析成像技术是量子信息技术的基石，它可以从测量统计数据中描述量子系统的特征并为其设定基准。在这项工作中，我们提出了一种基于不保真度的最小二乘估计器，它结合了状态纯度信息，比以往的层析准确度高出几个数量级。它通过直接保真度估计的随机工具箱得到了进一步增强，使其适用于大规模量子系统。我们在 IBM Qiskit 模拟器上进行了大量实验，验证了所提出的估计器。实验结果还证明，我们的估计器对于（近乎）纯态的保真度可随保利样本大小 N 而缩放。此外，它还能在给定一些状态先验的情况下，对多达 25 量子比特的系统进行高精度纯态层析。我们的方法为底层层析技术与状态特性估计的结合提供了一个新的视角。
{"title":"Quantum state tomography based on infidelity estimation","authors":"Yong Wang, Lijun Liu, Tong Dou, Li Li and Shuming Cheng","doi":"10.1088/2058-9565/ad92a4","DOIUrl":"https://doi.org/10.1088/2058-9565/ad92a4","url":null,"abstract":"Quantum state tomography is a cornerstone of quantum information technologies to characterize and benchmark quantum systems from measurement statistics. In this work, we present an infidelity-based least-squares estimator, which incorporates the state purity information and provides orders of magnitude higher tomography accuracy than previous ones. It is further enhanced with the randomized toolbox of direct fidelity estimation, making it applicable to large-scale quantum systems. We validate the proposed estimators through extensive experiments conducted on the IBM Qiskit simulator. The results also demonstrate that our estimator admits an infidelity scaling with Pauli sample size N for (nearly) pure states. Further, it enables high-precision pure-state tomography for systems of up to 25-qubit states, given some state priors. Our method provides a novel perspective on the union of underlying tomography technique and state properties estimation.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"16 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1088/1361-648X/ad912e
Priyanka Meena, Amarjyoti Choudhury, Mohit Mudgal, Sonika Bagga, V K Tiwari, Sarita Rajput, C S Yadav, Vivek Kumar Malik, T Maitra, Jayita Nayak
GdSiAl single crystal has been investigated by means of magnetic and magneto-transport measurements and compared withab-initiodensity functional theory (DFT) calculations. Significant non-saturating magnetoresistance reaching∼18%at 12T and2Kwas observed, alongside the presence of Shubnikov-de Haas oscillations with the fundamental frequencies 22.09T and 77.33T. Shubnikov-de Haas oscillations provide the information about the nontrivialπBerry phase in GdSiAl with the Fermi surface areas of0.00211A˚-2and0.00739A˚-2. Angle-dependent magnetoresistance shows anisotropy withθ, exhibiting a maximum at 180°. The magnetic susceptibility data forH∥candH⊥creveals that the magnetic moments of Gd3+ions orders antiferromagnetically below 32K along with an another transition occurs at∼8K, which is consistent with the heat capacity measurements where a distinctλ-shaped anomaly has been observed near antiferromagnetic ordering temperature 32K. The high value of Debye temperature indicates the contribution of acoustic phonons. Electronic structure calculations suggest the existence of nested Fermi surface pockets characterized by nesting wave vectors that closely align with the observed magnetic ordering wave vector. Furthermore, DFT calculations reveal the presence of Weyl nodes in close proximity to the Fermi surface. Our findings from combined experimental and theoretical techniques indicate GdSiAl to be a potential candidate for an antiferromagnetic topological Weyl semimetal.
{"title":"Exploration of quantum oscillation in antiferromagnetic Weyl semimetal GdSiAl.","authors":"Priyanka Meena, Amarjyoti Choudhury, Mohit Mudgal, Sonika Bagga, V K Tiwari, Sarita Rajput, C S Yadav, Vivek Kumar Malik, T Maitra, Jayita Nayak","doi":"10.1088/1361-648X/ad912e","DOIUrl":"10.1088/1361-648X/ad912e","url":null,"abstract":"<p><p>GdSiAl single crystal has been investigated by means of magnetic and magneto-transport measurements and compared with<i>ab-initio</i>density functional theory (DFT) calculations. Significant non-saturating magnetoresistance reaching∼18%at 12T and2Kwas observed, alongside the presence of Shubnikov-de Haas oscillations with the fundamental frequencies 22.09T and 77.33T. Shubnikov-de Haas oscillations provide the information about the nontrivial<i>π</i>Berry phase in GdSiAl with the Fermi surface areas of0.00211A˚-2and0.00739A˚-2. Angle-dependent magnetoresistance shows anisotropy with<i>θ</i>, exhibiting a maximum at 180°. The magnetic susceptibility data forH∥candH⊥creveals that the magnetic moments of Gd<sup>3+</sup>ions orders antiferromagnetically below 32K along with an another transition occurs at∼8K, which is consistent with the heat capacity measurements where a distinct<i>λ</i>-shaped anomaly has been observed near antiferromagnetic ordering temperature 32K. The high value of Debye temperature indicates the contribution of acoustic phonons. Electronic structure calculations suggest the existence of nested Fermi surface pockets characterized by nesting wave vectors that closely align with the observed magnetic ordering wave vector. Furthermore, DFT calculations reveal the presence of Weyl nodes in close proximity to the Fermi surface. Our findings from combined experimental and theoretical techniques indicate GdSiAl to be a potential candidate for an antiferromagnetic topological Weyl semimetal.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1088/1361-648X/ad92d5
Somnath Sahu, Shashi Priya Balmuchu, Pamu Dobbidi
Ferrite thin films are explored due to their promising properties, which are essential in various advanced electronic devices. However, depositing a film with pure phase and uniform microstructure is challenging. The Ni0.5Co0.5Fe2O4ferrite thin films are deposited using pulsed laser deposition technique to explore the effect of thickness on structural properties, growth evolution, temperature-dependent dielectric behavior, and conduction mechanisms. Microstructural analysis revealed that the films are uniformly grown, exhibiting surface roughness ranging from ∼2 to 4 nm. The dielectric response, adhering to a modified Debye model, exhibited multiple relaxation processes, with notable changes in the dielectric constant and loss as film thickness increased. Impedance spectra exhibited both space charge and dipolar relaxation phenomena, corroborated by Cole-Cole and electrical modulus plots. The analysis of the imaginary electric modulus using the Kohlrausch-Williams-Watts function revealed non-Debye-type relaxation in all deposited films, characterized by thermally activated broad peaks. Conductivity decreased up to a certain film thickness, and the frequency exponent derived from Jonscher's power law suggested a correlated barrier hopping model for AC conduction. Activation energies improved with film thickness up to 125 nm, consistent with a constant energy barrier for polarons during relaxation and conduction phases. The film with 125 nm thickness exhibited the optimal dielectric properties, with the maximum dielectric constant, minimum dielectric loss, and highest activation energy. These findings highlight the potential of dense, uniformly grown films with high dielectric constants and low dielectric losses for advanced electronic device applications.
{"title":"Thickness-dependent structural and growth evolution in relation to dielectric relaxation behavior and correlated barrier hopping conduction mechanism in Ni<sub>0.5</sub>Co<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>ferrite thin films.","authors":"Somnath Sahu, Shashi Priya Balmuchu, Pamu Dobbidi","doi":"10.1088/1361-648X/ad92d5","DOIUrl":"10.1088/1361-648X/ad92d5","url":null,"abstract":"<p><p>Ferrite thin films are explored due to their promising properties, which are essential in various advanced electronic devices. However, depositing a film with pure phase and uniform microstructure is challenging. The Ni<sub>0.5</sub>Co<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>ferrite thin films are deposited using pulsed laser deposition technique to explore the effect of thickness on structural properties, growth evolution, temperature-dependent dielectric behavior, and conduction mechanisms. Microstructural analysis revealed that the films are uniformly grown, exhibiting surface roughness ranging from ∼2 to 4 nm. The dielectric response, adhering to a modified Debye model, exhibited multiple relaxation processes, with notable changes in the dielectric constant and loss as film thickness increased. Impedance spectra exhibited both space charge and dipolar relaxation phenomena, corroborated by Cole-Cole and electrical modulus plots. The analysis of the imaginary electric modulus using the Kohlrausch-Williams-Watts function revealed non-Debye-type relaxation in all deposited films, characterized by thermally activated broad peaks. Conductivity decreased up to a certain film thickness, and the frequency exponent derived from Jonscher's power law suggested a correlated barrier hopping model for AC conduction. Activation energies improved with film thickness up to 125 nm, consistent with a constant energy barrier for polarons during relaxation and conduction phases. The film with 125 nm thickness exhibited the optimal dielectric properties, with the maximum dielectric constant, minimum dielectric loss, and highest activation energy. These findings highlight the potential of dense, uniformly grown films with high dielectric constants and low dielectric losses for advanced electronic device applications.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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