QUROPE Quantum Information Processing and Communication in Europe

Author(s): Yu Tao, Xinhang Li, Lang Li, Jingzheng Huang, Hongjing Li, Tao Wang, Linjie Zhou, and Guihua Zeng

Bosonic loss estimation has an important role in quantum metrology. It was once believed that the ultimate precision of this task is restricted to the standard quantum limit if no quantum probe is involved. Nevertheless, a recent proposal showed that this limit can be surpassed by utilizing ring res…

[Phys. Rev. Lett. 133, 060801] Published Tue Aug 06, 2024

Author(s): Ryan Wilkinson

Researchers have used a specially crafted electric potential to manipulate the electronic band structure of graphene, laying the groundwork for on-demand electronic band design.

[Physics 17, s92] Published Tue Aug 06, 2024

Author(s): Kaiming Bian, Shitao Zhang, Fei Meng, Wen Zhang, and Oscar Dahlsten

Many supervised learning tasks have intrinsic symmetries, such as translational and rotational symmetry in image classifications. These symmetries can be exploited to enhance performance. We formulate the symmetry constraints into a concise mathematical form. We design two ways to adopt the constrai…

[Phys. Rev. A 110, 022406] Published Mon Aug 05, 2024

Author(s): Jihao Ma, Jungeng Zhou, Jiahao Huang, and Chaohong Lee

One-axis twisting (OAT) and two-axis twisting (TAT) are well-known methods for achieving entanglement-enhanced quantum metrology, and their time-reversal echo offers a potent tool for approaching the Heisenberg limit even with detection noise. However, flipping the sign of interaction to implement t…

[Phys. Rev. A 110, 022407] Published Mon Aug 05, 2024

Author(s): Botao Du, Ramya Suresh, Santiago López, Jeremy Cadiente, and Ruichao Ma

Transport measurements are fundamental for understanding condensed matter phenomena, from superconductivity to the fractional quantum Hall effect. Analogously, they can be powerful tools for probing synthetic quantum matter in quantum simulators. Here we demonstrate the measurement of in situ partic…

[Phys. Rev. Lett. 133, 060601] Published Mon Aug 05, 2024

Author(s): Annabelle Bohrdt

A new manipulation technique could enable the realization of more versatile quantum simulators.

[Physics 17, 120] Published Mon Aug 05, 2024

Author(s): Keitaro Anai, Shion Ikehara, Yoshichika Yano, Daichi Okuno, and Shuntaro Takeda

Among various quantum machine learning (QML) algorithms, the quantum kernel method has especially attracted attention due to its compatibility with noisy intermediate-scale quantum devices and its potential to achieve quantum advantage. This method performs classification and regression by nonlinear…

[Phys. Rev. A 110, 022404] Published Fri Aug 02, 2024

Author(s): Victor F. dos Santos and Jonas Maziero

Recently, the entanglement dynamics of two harmonic oscillators initially prepared in a separable-coherent state was demonstrated to offer a pathway for prime number identification. This article presents a generalized approach and outlines a deterministic algorithm making possible the implementation…

[Phys. Rev. A 110, 022405] Published Fri Aug 02, 2024

Author(s): Nicolò Defenu, David Mukamel, and Stefano Ruffo

Ensemble inequivalence, i.e., the possibility of observing different thermodynamic properties depending on the statistical ensemble which describes the system, is one of the hallmarks of long-range physics, which has been demonstrated in numerous classical systems. Here, an example of ensemble inequ…

[Phys. Rev. Lett. 133, 050403] Published Fri Aug 02, 2024

Author(s): Eric Vernier, Hsiu-Chung Yeh, Lorenzo Piroli, and Aditi Mitra

Robust edge modes exist for a class of integrable spin chains in the interacting Floquet setting.

[Phys. Rev. Lett. 133, 050606] Published Fri Aug 02, 2024

Author(s): Mark Buchanan

New data on the rotation around both long and short axes of plastic strands may help researchers track and remove microplastics that pollute the ocean.

[Physics 17, 122] Published Fri Aug 02, 2024

Author(s): Li-Na Zheng, Xiu-Yun Zhang, Ai-Lei He, and Lu Qi

We show that both the efficiency and robustness of the topological excitation transmission can be optimized by the phase factor of the long-range hopping in the dimerized lattice. This phenomenon can be explained as the fact that the phase factor in the hopping can widen the minimal energy space aro…

[Phys. Rev. A 110, 022401] Published Thu Aug 01, 2024

Author(s): Yijia Xu (许逸葭), Yixu Wang (王亦许), and Victor V. Albert

We develop quantum information processing primitives for the planar rotor, the state space of a particle on a circle. The n-rotor Clifford group, U(1)n(n+1)/2⋊GLn(Z), is represented by continuous U(1) gates generated by polynomials quadratic in angular momenta, as well as discrete GLn(Z) gates gener…

[Phys. Rev. A 110, 022402] Published Thu Aug 01, 2024

Author(s): Haozhen Situ, Zhimin He, Shenggen Zheng, and Lvzhou Li

Variational quantum algorithms, inspired by neural networks, have become a novel approach in quantum computing. However, designing efficient parameterized quantum circuits remains a challenge. Quantum architecture search tackles this by adjusting circuit structures along with gate parameters to auto…

[Phys. Rev. A 110, 022403] Published Thu Aug 01, 2024

Author(s): Brendan Pankovich, Angus Kan, Kwok Ho Wan, Maike Ostmann, Alex Neville, Srikrishna Omkar, Adel Sohbi, and Kamil Brádler

We propose fault-tolerant architectures based on performing projective measurements in the Greenberger–Horne–Zeilinger (GHZ) basis on constant-sized, entangled resource states. We present linear-optical constructions of the architectures, where the GHZ-state measurements are encoded to suppress the …

[Phys. Rev. Lett. 133, 050604] Published Thu Aug 01, 2024

Author(s): Wooyeong Song, Nuri Kang, Yong-Su Kim, and Seung-Woo Lee

We propose a fault-tolerant quantum computation scheme in a measurement-based manner with finite-sized entangled resource states and encoded-fusion scheme with linear optics. The encoded fusion is an entangled measurement devised to enhance the fusion success probability in the presence of losses an…

[Phys. Rev. Lett. 133, 050605] Published Thu Aug 01, 2024

Author(s): Charles Day

A correlation between two astronomical observables reveals the influence of visible matter on a universe dominated by dark matter.

[Physics 17, s86] Published Thu Aug 01, 2024

Author(s): Pedro Rosario, Alan C. Santos, Nicola Piovella, Robin Kaiser, André Cidrim, and Romain Bachelard

To address the outstanding task of detecting entanglement in large quantum systems, entanglement witnesses have emerged, addressing the separable nature of a state. Yet optimizing witnesses, or accessing them experimentally, often remains a challenge. We here introduce a family of entanglement witne…

[Phys. Rev. Lett. 133, 050203] Published Wed Jul 31, 2024

Author(s): Y. S. Teo, S. U. Shringarpure, H. Jeong, N. Prasannan, B. Brecht, C. Silberhorn, M. Evans, D. Mogilevtsev, and L. L. Sánchez-Soto

Identifying a reasonably small Hilbert space that completely describes an unknown quantum state is crucial for efficient quantum information processing. We introduce a general dimension-certification protocol for both discrete and continuous variables that is fully evidence based, relying solely on …

[Phys. Rev. Lett. 133, 050204] Published Wed Jul 31, 2024

Author(s): Tobias Haug and M. S. Kim

Generalization is the ability of machine learning models to make accurate predictions on new data by learning from training data. However, understanding generalization of quantum machine learning models has been a major challenge. Here, we introduce the data quantum Fisher information metric (DQFIM)…

[Phys. Rev. Lett. 133, 050603] Published Wed Jul 31, 2024