Journals

Hybrid quantum-gap-estimation algorithm using a filtered time series

PRA: Quantum information - Wed, 2024-05-01 12:00

Author(s): Woo-Ram Lee, Ryan Scott, and V. W. Scarola

Quantum simulation advantage over classical memory limitations would allow compact quantum circuits to yield insight into intractable quantum many-body problems, but the interrelated obstacles of large circuit depth in quantum time evolution and noise seem to rule out unbiased quantum simulation in …


[Phys. Rev. A 109, 052403] Published Wed May 01, 2024

Categories: Journals, Physics

Dynamics of qudit gates and effects of spectator modes on optimal control pulses

PRA: Quantum information - Wed, 2024-05-01 12:00

Author(s): A. Barış Özgüler and Joshua A. Job

Qudit gates for high-dimensional quantum computing can be synthesized with high precision using numerical quantum optimal control techniques. Large circuits are broken down into modules and the tailored pulses for each module can be used as primitives for a qudit compiler. Application of the pulses …


[Phys. Rev. A 109, 052404] Published Wed May 01, 2024

Categories: Journals, Physics

Boosting coherence-based protocols with correlated catalysts

PRA: Quantum information - Wed, 2024-05-01 12:00

Author(s): Priyabrata Char, Ajoy Sen, Amit Bhar, Indrani Chattopadhyay, and Debasis Sarkar

We explore the potential impact of the recently introduced correlated approximate catalytic procedure on quantum information processing tasks, particularly focusing on phase and subchannel discrimination protocols. Our findings reveal that the correlated catalyst substantially enhances the efficienc…


[Phys. Rev. A 109, 052405] Published Wed May 01, 2024

Categories: Journals, Physics

Tight Bounds on Pauli Channel Learning without Entanglement

Author(s): Senrui Chen, Changhun Oh, Sisi Zhou, Hsin-Yuan Huang, and Liang Jiang

Quantum entanglement is a crucial resource for learning properties from nature, but a precise characterization of its advantage can be challenging. In this Letter, we consider learning algorithms without entanglement to be those that only utilize states, measurements, and operations that are separab…


[Phys. Rev. Lett. 132, 180805] Published Wed May 01, 2024

Categories: Journals, Physics

Asymmetric entanglement for quantum target sensing

PRA: Quantum information - Tue, 2024-04-30 12:00

Author(s): Su-Yong Lee, Jihwan Kim, Zaeill Kim, and Duk Y. Kim

Entanglement is beneficial to enhancing a phase sensitivity beyond the classical limit that is given by a coherent state. The best performance is achieved with symmetric entangled states, which is enhanced further by sending more photons to the signal mode. We delve into which entanglement structure…


[Phys. Rev. A 109, 042429] Published Tue Apr 30, 2024

Categories: Journals, Physics

Universal and robust quantum coherent control based on a chirped-pulse driving protocol

PRA: Quantum information - Tue, 2024-04-30 12:00

Author(s): Yue-Hao Yin, Jin-Xin Yang, and Li-Xiang Cen

We propose a chirped-pulse driving protocol and reveal its exceptional property for quantum coherent control. The nonadiabatic passage generated by the driving protocol, which includes the population inversion and the nonadiabaticity-induced transition as its ingredients, is shown to be robust again…


[Phys. Rev. A 109, 042430] Published Tue Apr 30, 2024

Categories: Journals, Physics

Energy-Conversion Device Using a Quantum Engine with the Work Medium of Two-Atom Entanglement

Author(s): J.-W. Zhang, B. Wang, W.-F. Yuan, J.-C. Li, J.-T. Bu, G.-Y. Ding, W.-Q. Ding, L. Chen, F. Zhou, and M. Feng

Although entanglement is considered as an essential resource for quantum information processing, whether entanglement helps for energy conversion or output in the quantum regime is still lack of experimental witness. Here, we report on an energy-conversion device operating as a quantum engine with t…


[Phys. Rev. Lett. 132, 180401] Published Tue Apr 30, 2024

Categories: Journals, Physics

New Constraints on Exotic Spin-Spin-Velocity-Dependent Interactions with Solid-State Quantum Sensors

Author(s): Yue Huang, Hang Liang, Man Jiao, Pei Yu, Xiangyu Ye, Yijin Xie, Yi-Fu Cai, Chang-Kui Duan, Ya Wang, Xing Rong, and Jiangfeng Du

We report new experimental results on exotic spin-spin-velocity-dependent interactions between electron spins. We designed an elaborate setup that is equipped with two nitrogen-vacancy (NV) ensembles in diamonds. One of the NV ensembles serves as the spin source, while the other functions as the spi…


[Phys. Rev. Lett. 132, 180801] Published Tue Apr 30, 2024

Categories: Journals, Physics

Estimation with Ultimate Quantum Precision of the Transverse Displacement between Two Photons via Two-Photon Interference Sampling Measurements

Author(s): Danilo Triggiani and Vincenzo Tamma

We present a quantum sensing scheme achieving the ultimate quantum sensitivity in the estimation of the transverse displacement between two photons interfering at a balanced beam splitter, based on transverse-momentum sampling measurements at the output. This scheme can possibly lead to enhanced hig…


[Phys. Rev. Lett. 132, 180802] Published Tue Apr 30, 2024

Categories: Journals, Physics

Evaluating the efficiency of ground-state-preparation algorithms

PRA: Quantum information - Mon, 2024-04-29 12:00

Author(s): Katerina Gratsea, Chong Sun, and Peter D. Johnson

In recent years, substantial research effort has been devoted to quantum algorithms for ground-state-energy estimation (GSEE) in chemistry and materials. Given the many heuristic and nonheuristic methods being developed, it is challenging to assess what combination of these methods will ultimately b…


[Phys. Rev. A 109, 042425] Published Mon Apr 29, 2024

Categories: Journals, Physics

Robustness of variational quantum algorithms against stochastic parameter perturbation

PRA: Quantum information - Mon, 2024-04-29 12:00

Author(s): Daniil Rabinovich, Ernesto Campos, Soumik Adhikary, Ekaterina Pankovets, Dmitry Vinichenko, and Jacob Biamonte

Variational quantum algorithms are tailored to perform within the constraints of current quantum devices, yet they are limited by performance-degrading errors. In this study we consider a noise model that reflects realistic gate errors inherent to variational quantum algorithms. We investigate the d…


[Phys. Rev. A 109, 042426] Published Mon Apr 29, 2024

Categories: Journals, Physics

Error-corrected quantum repeaters with Gottesman-Kitaev-Preskill qudits

PRA: Quantum information - Mon, 2024-04-29 12:00

Author(s): Frank Schmidt, Daniel Miller, and Peter van Loock

The authors theoretically analyze the performance of long-distance quantum communication protocols, specifically quantum repeaters based on Gottesman-Kitaev-Preskill (GKP) qudits. Previously, only the qubit case has been studied. They construct three quantum repeater schemes and find that, while in most cases any benefits of using higher dimensions is negated by worse error correction, there are some regimes where the use of qubits does increase the secret key rate.


[Phys. Rev. A 109, 042427] Published Mon Apr 29, 2024

Categories: Journals, Physics

Machine-learning-inspired quantum control in many-body dynamics

PRA: Quantum information - Mon, 2024-04-29 12:00

Author(s): Meng-Yun Mao, Zheng Cheng, Liangsheng Li, Ning Wu, and Wen-Long You

Achieving precise preparation of quantum many-body states is crucial for the practical implementation of quantum computation and quantum simulation. However, the inherent challenges posed by unavoidable excitations at critical points during quench processes necessitate careful design of control fiel…


[Phys. Rev. A 109, 042428] Published Mon Apr 29, 2024

Categories: Journals, Physics

Submicrosecond high-fidelity dispersive readout of a spin qubit with squeezed photons

PRA: Quantum information - Mon, 2024-04-29 12:00

Author(s): Chon-Fai Kam and Xuedong Hu

This work focuses on enhancing the dispersive readout of a single electron spin qubit by utilizing displaced squeezed vacuum states for the probe photons. The built-in quantum correlations of squeezed photons lead to significant improvements in qubit readout fidelity and speed.


[Phys. Rev. A 109, L040402] Published Mon Apr 29, 2024

Categories: Journals, Physics

Local-projective-measurement-enhanced quantum battery capacity

PRA: Quantum information - Fri, 2024-04-26 12:00

Author(s): Tinggui Zhang, Hong Yang, and Shao-Ming Fei

Quantum batteries have significant potential applications for future industry and daily life. The capacity is an important indicator for a battery. Methods to improve the capacity of quantum batteries are important. We consider quantum batteries given by bipartite quantum systems and study the enhan…


[Phys. Rev. A 109, 042424] Published Fri Apr 26, 2024

Categories: Journals, Physics

Gottesman-Kitaev-Preskill Encoding in Continuous Modal Variables of Single Photons

Author(s): Éloi Descamps, Arne Keller, and Pérola Milman

GKP states, introduced by Gottesman, Kitaev, and Preskill, are continuous variable logical qubits that can be corrected for errors caused by phase space displacements. Their experimental realization is challenging, in particular, using propagating fields, where quantum information is encoded in the …


[Phys. Rev. Lett. 132, 170601] Published Fri Apr 26, 2024

Categories: Journals, Physics

Separability Transitions in Topological States Induced by Local Decoherence

Author(s): Yu-Hsueh Chen and Tarun Grover

We study states with intrinsic topological order subjected to local decoherence from the perspective of separability, i.e., whether a decohered mixed state can be expressed as an ensemble of short-range entangled pure states. We focus on toric codes and the X-cube fracton state and provide evidence …


[Phys. Rev. Lett. 132, 170602] Published Fri Apr 26, 2024

Categories: Journals, Physics

Closed-Form Propagator of the Calogero Model

Author(s): Valdemar Melin and Edwin Langmann

We present a generalization of the Mehler kernel, providing the exact analytic time evolution of the Calogero model that describes bosons or fermions propagating on the real line with inverse-square two-body interactions and harmonic confinement. The key to our result is a simple relation between th…


[Phys. Rev. Lett. 132, 170201] Published Thu Apr 25, 2024

Categories: Journals, Physics

Dynamics of a Quantum System Interacting with White Non-Gaussian Baths: Poisson Noise Master Equation

Author(s): Ken Funo and Akihito Ishizaki

Quantum systems are unavoidably open to their surrounding degrees of freedom. The theory of open quantum systems is thus crucial to understanding the fluctuations, dissipation, and decoherence of a quantum system of interest. Typically, the bath is modeled as an ensemble of harmonic oscillators, whi…


[Phys. Rev. Lett. 132, 170402] Published Thu Apr 25, 2024

Categories: Journals, Physics

Quantifying nonstabilizerness through entanglement spectrum flatness

PRA: Quantum information - Wed, 2024-04-24 12:00

Author(s): Emanuele Tirrito, Poetri Sonya Tarabunga, Gugliemo Lami, Titas Chanda, Lorenzo Leone, Salvatore F. E. Oliviero, Marcello Dalmonte, Mario Collura, and Alioscia Hamma

The authors establish a connection between nonstabilizerness and a readily measurable property – the entanglement spectrum. This connection not only provides a deeper understanding of quantum complexity but also offers a practical way to probe nonstabilizerness even in noisy environments.


[Phys. Rev. A 109, L040401] Published Wed Apr 24, 2024

Categories: Journals, Physics
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