Physics

Quantum State Tomography via Nonconvex Riemannian Gradient Descent

Author(s): Ming-Chien Hsu, En-Jui Kuo, Wei-Hsuan Yu, Jian-Feng Cai, and Min-Hsiu Hsieh

The recovery of an unknown density matrix of large size requires huge computational resources. State-of-the-art performance has recently been achieved with the factored gradient descent (FGD) algorithm and its variants since they are able to mitigate the dimensionality barrier by utilizing some of t…


[Phys. Rev. Lett. 132, 240804] Published Thu Jun 13, 2024

Categories: Journals, Physics

Gravitational-Wave Memory May Illustrate Spacetime Symmetries

APS Physics - Thu, 2024-06-13 12:00

Author(s): Elizabeth Fernandez

Observing gravitational-wave memory may help physicists test general relativity predictions about large-scale symmetries in the fabric of spacetime.


[Physics 17, 95] Published Thu Jun 13, 2024

Categories: Physics

Adding Certainty to Plutonium’s Fission Yield

APS Physics - Thu, 2024-06-13 12:00

Author(s): Rachel Berkowitz

A first-of-its-kind measurement reveals the energy spectrum of the neutrons produced during the fission of plutonium, a common nuclear fuel component.


[Physics 17, s68] Published Thu Jun 13, 2024

Categories: Physics

Information carried by a single particle in quantum multiple-access channels

PRA: Quantum information - Thu, 2024-06-13 12:00

Author(s): Xinan Chen, Yujie Zhang, Andreas Winter, Virginia O. Lorenz, and Eric Chitambar

Nonclassical features of quantum systems have the potential to strengthen the way we currently exchange information. In this paper, we explore this enhancement on the most basic level of single particles. To be more precise, we compare how well multiparty information can be transmitted to a single r…


[Phys. Rev. A 109, 062420] Published Thu Jun 13, 2024

Categories: Journals, Physics

Identification of a natural fieldlike entanglement resource in trapped-ion chains

PRA: Quantum information - Thu, 2024-06-13 12:00

Author(s): Natalie Klco and D. H. Beck

The electromagnetic trapping of ion chains can be regarded as a process of nontrivial entangled quantum state preparation within Hilbert spaces of the local axial motional modes. To begin uncovering properties of this entanglement resource produced as a by-product of conventional ion-trap quantum in…


[Phys. Rev. A 109, 062419] Published Thu Jun 13, 2024

Categories: Journals, Physics

Self-Consistent Many-Body Metrology

Author(s): Jae-Gyun Baak and Uwe R. Fischer

We investigate the classical and quantum metrology of performing parameter estimation with interacting trapped bosons, which we theoretically treat by a self-consistent many-body approach of the multiconfigurational Hartree type. Focusing on a tilted double-well geometry, we compare a self-consisten…


[Phys. Rev. Lett. 132, 240803] Published Wed Jun 12, 2024

Categories: Journals, Physics

A Step toward Quantum Gases of Doubly Polar Molecules

APS Physics - Wed, 2024-06-12 12:00

Author(s): David Ehrenstein

Researchers created an ultracold gas of molecules with strong magnetic dipoles, which may lead to new types of Bose-Einstein condensates.


[Physics 17, s73] Published Wed Jun 12, 2024

Categories: Physics

User-friendly confidence regions for quantum state tomography

PRA: Quantum information - Wed, 2024-06-12 12:00

Author(s): Carlos de Gois and Matthias Kleinmann

Quantum state tomography is the standard technique for reconstructing a quantum state from experimental data. In the regime of finite statistics, experimental data cannot give perfect information about the quantum state. A common way to express this limited knowledge is by providing confidence regio…


[Phys. Rev. A 109, 062417] Published Wed Jun 12, 2024

Categories: Journals, Physics

Reexamination of quantum state transformations with zero communication

PRA: Quantum information - Wed, 2024-06-12 12:00

Author(s): Ian George and Eric Chitambar

It is known that general convertibility of bipartite entangled states is not possible to arbitrary error without some classical communication. While some tradeoffs between communication cost and conversion error have been proven, these bounds can be very loose. In particular, there are many cases in…


[Phys. Rev. A 109, 062418] Published Wed Jun 12, 2024

Categories: Journals, Physics

Partial-transpose-guided entanglement classes and minimum noise filtering in many-body Gaussian quantum systems

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Boyu Gao and Natalie Klco

The reduction and distortion of quantum correlations in the presence of classical noise leads to varied levels of inefficiency in the availability of entanglement as a resource for quantum information processing protocols. While generically minimizing required entanglement for mixed quantum states r…


[Phys. Rev. A 109, 062413] Published Tue Jun 11, 2024

Categories: Journals, Physics

Quantum control for the Zeno effect with noise

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Haorui Chen and Shengshi Pang

The quantum Zeno effect is a distinctive phenomenon in quantum mechanics, describing the nontrivial effect of frequent projective measurements on hindering the evolution of a quantum system. However, when subjected to environmental noise, the quantum system may dissipate, and the quantum Zeno effect…


[Phys. Rev. A 109, 062414] Published Tue Jun 11, 2024

Categories: Journals, Physics

Dual-frame optimization for informationally complete quantum measurements

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Laurin E. Fischer, Timothée Dao, Ivano Tavernelli, and Francesco Tacchino

Randomized measurement protocols such as classical shadows represent powerful resources for quantum technologies, with applications ranging from quantum state characterization and process tomography to machine learning and error mitigation. Recently, the notion of measurement dual frames, in which c…


[Phys. Rev. A 109, 062415] Published Tue Jun 11, 2024

Categories: Journals, Physics

One-shot and asymptotic classical capacity in general physical theories

PRA: Quantum information - Tue, 2024-06-11 12:00

Author(s): Shintaro Minagawa and Hayato Arai

With the recent development of quantum information theory, some attempts have been made to construct information theory beyond quantum theory. Here, we consider hypothesis-testing relative entropy and one-shot classical capacity, that is, the optimal rate of classical information transmitted by usin…


[Phys. Rev. A 109, 062416] Published Tue Jun 11, 2024

Categories: Journals, Physics

Measurement-Based Infused Circuits for Variational Quantum Eigensolvers

Author(s): Albie Chan, Zheng Shi, Luca Dellantonio, Wolfgang Dür, and Christine A. Muschik

Variational quantum eigensolvers (VQEs) are successful algorithms for studying physical systems on quantum computers. Recently, they were extended to the measurement-based model of quantum computing, bringing resource graph states and their advantages into the realm of quantum simulation. In this Le…


[Phys. Rev. Lett. 132, 240601] Published Tue Jun 11, 2024

Categories: Journals, Physics

Certifying Network Topologies and Nonlocalities of Triangle Quantum Networks

Author(s): Ya-Li Mao, Hu Chen, Bixiang Guo, Shiting Liu, Zheng-Da Li, Ming-Xing Luo, and Jingyun Fan

Quantum networks promise unprecedented advantages in information processing and open up intriguing new opportunities in fundamental research, where network topology and network nonlocality fundamentally underlie these applications. Hence, the detections of network topology and nonlocality are crucia…


[Phys. Rev. Lett. 132, 240801] Published Tue Jun 11, 2024

Categories: Journals, Physics

Certifying the Topology of Quantum Networks: Theory and Experiment

Author(s): Lisa T. Weinbrenner, Nidhin Prasannan, Kiara Hansenne, Sophia Denker, Jan Sperling, Benjamin Brecht, Christine Silberhorn, and Otfried Gühne

Distributed quantum information in networks is paramount for global secure quantum communication. Moreover, it finds applications as a resource for relevant tasks, such as clock synchronization, magnetic field sensing, and blind quantum computation. For quantum network analysis and benchmarking of i…


[Phys. Rev. Lett. 132, 240802] Published Tue Jun 11, 2024

Categories: Journals, Physics

Extending the Kibble-Zurek Mechanism

APS Physics - Tue, 2024-06-11 12:00

Author(s): Charles Day

A theory first applied to phase transitions in the early Universe and then to defects in superfluid helium can now account for a wider variety of systems.


[Physics 17, s61] Published Tue Jun 11, 2024

Categories: Physics

All-optical correlated noisy channel and its application in recovering quantum coherence

PRA: Quantum information - Mon, 2024-06-10 12:00

Author(s): Dan Lei, Disheng Guo, Jun Xin, and Xiao-Ming Lu

Attenuation and amplification are the most common processes for optical communications. Amplification can be used to compensate the attenuation of the complex amplitude of an optical field, but is unable to recover the coherence lost, provided that the attenuation channel and the amplification chann…


[Phys. Rev. A 109, 062410] Published Mon Jun 10, 2024

Categories: Journals, Physics

Concatenating quantum error-correcting codes with decoherence-free subspaces and vice versa

PRA: Quantum information - Mon, 2024-06-10 12:00

Author(s): Nihar Ranjan Dash, Sanjoy Dutta, R. Srikanth, and Subhashish Banerjee

Quantum error-correcting codes (QECCs) and decoherence-free subspace (DFS) codes provide active and passive means, respectively, to address certain types of errors that arise during quantum computation. The latter technique is suitable to correct correlated errors with certain symmetries and the for…


[Phys. Rev. A 109, 062411] Published Mon Jun 10, 2024

Categories: Journals, Physics

Enhanced observable estimation through classical optimization of informationally overcomplete measurement data: Beyond classical shadows

PRA: Quantum information - Mon, 2024-06-10 12:00

Author(s): Joonas Malmi, Keijo Korhonen, Daniel Cavalcanti, and Guillermo García-Pérez

In recent years, informationally complete measurements have attracted considerable attention, especially in the context of classical shadows. In the particular case of informationally overcomplete measurements, for which the number of possible outcomes exceeds the dimension of the space of linear op…


[Phys. Rev. A 109, 062412] Published Mon Jun 10, 2024

Categories: Journals, Physics
Syndicate content