Physics

Simulating the spin-boson model with a controllable reservoir in an ion trap

PRA: Quantum information - Mon, 2024-06-03 12:00

Author(s): G.-X. Wang, Y.-K. Wu, R. Yao, W.-Q. Lian, Z.-J. Cheng, Y.-L. Xu, C. Zhang, Y. Jiang, Y.-Z. Xu, B.-X. Qi, P.-Y. Hou, Z.-C. Zhou, L. He, and L.-M. Duan

The spin-boson model is a prototypical model for open quantum dynamics. Here we simulate the spin-boson model using a chain of trapped ions in which a spin is coupled to a structured reservoir of bosonic modes. We engineer the spectral density of the reservoir by adjusting the ion number, the target…


[Phys. Rev. A 109, 062402] Published Mon Jun 03, 2024

Categories: Journals, Physics

Investigating controlled teleportation capability of quantum states with respect to $k$-separability

PRA: Quantum information - Mon, 2024-06-03 12:00

Author(s): Minjin Choi, Jeonghyeon Shin, Gunho Lee, and Eunok Bae

Quantum teleportation is an essential application of quantum entanglement. The examination of teleportation fidelity in two-party standard teleportation schemes reveals a critical threshold distinguishing separable and entangled states. For separable states, their teleportation fidelities cannot exc…


[Phys. Rev. A 109, 062403] Published Mon Jun 03, 2024

Categories: Journals, Physics

Active learning for quantum mechanical measurements

PRA: Quantum information - Mon, 2024-06-03 12:00

Author(s): Ruidi Zhu, Ciara Pike-Burke, and Florian Mintert

The experimental evaluation of many quantum mechanical quantities requires the estimation of several directly measurable observables, such as local observables. Due to the necessity to repeat experiments on individual quantum systems in order to estimate expectation values of observables, the questi…


[Phys. Rev. A 109, 062404] Published Mon Jun 03, 2024

Categories: Journals, Physics

Sufficient conditions, lower bounds, and trade-off relations for quantumness in Kirkwood-Dirac quasiprobability

PRA: Quantum information - Mon, 2024-06-03 12:00

Author(s): Agung Budiyono

Kirkwood-Dirac (KD) quasiprobability is a quantum analog of classical phase space probability. It offers an informationally complete representation of quantum state wherein the quantumness associated with quantum noncommutativity manifests in its nonclassical values, i.e., the nonreal and/or negativ…


[Phys. Rev. A 109, 062405] Published Mon Jun 03, 2024

Categories: Journals, Physics

Classical shadow tomography with mutually unbiased bases

PRA: Quantum information - Mon, 2024-06-03 12:00

Author(s): Yu Wang and Wei Cui

Classical shadow tomography, harnessing randomized informationally complete (IC) measurements, provides an effective avenue for predicting many properties of unknown quantum states. In n-qubit systems, projections onto 2n+1 mutually unbiased bases (MUBs) are widely recognized as minimal and optimal …


[Phys. Rev. A 109, 062406] Published Mon Jun 03, 2024

Categories: Journals, Physics

Efficient Initialization of Fluxonium Qubits based on Auxiliary Energy Levels

Author(s): Tenghui Wang, Feng Wu, Fei Wang, Xizheng Ma, Gengyan Zhang, Jianjun Chen, Hao Deng, Ran Gao, Ruizi Hu, Lu Ma, Zhijun Song, Tian Xia, Make Ying, Huijuan Zhan, Hui-Hai Zhao, and Chunqing Deng

Fast and high-fidelity qubit initialization is crucial for low-frequency qubits such as fluxonium, and in applications of many quantum algorithms and quantum error correction codes. In a circuit quantum electrodynamics system, the initialization is typically achieved by transferring the state betwee…


[Phys. Rev. Lett. 132, 230601] Published Mon Jun 03, 2024

Categories: Journals, Physics

Drug-Resistance Mutations Find Strength in Small Numbers

APS Physics - Mon, 2024-06-03 12:00

Author(s): Kirill Korolev

A new model, vetted by experiments on lung cancer cells, may help to explain how cancer and other diseases accumulate drug-resistance mutations that can compromise the effectiveness of treatments.


[Physics 17, 90] Published Mon Jun 03, 2024

Categories: Physics

High Schmidt Number Concentration in Quantum Bound Entangled States

Author(s): Robin Krebs and Mariami Gachechiladze

A deep understanding of quantum entanglement is vital for advancing quantum technologies. The strength of entanglement can be quantified by counting the degrees of freedom that are entangled, which results in a quantity called the Schmidt number. A particular challenge is to identify the strength of…


[Phys. Rev. Lett. 132, 220203] Published Fri May 31, 2024

Categories: Journals, Physics

Chiral Basis for Qubits and Spin-Helix Decay

Author(s): Vladislav Popkov, Xin Zhang, Frank Göhmann, and Andreas Klümper

We propose a qubit basis composed of transverse spin helices with kinks. Unlike the usual computational basis, this chiral basis is well-suited for describing quantum states with nontrivial topology. Choosing appropriate parameters the operators of the transverse spin components, σnx and σny, become…


[Phys. Rev. Lett. 132, 220404] Published Fri May 31, 2024

Categories: Journals, Physics

Local Integrals of Motion in Dipole-Conserving Models with Hilbert Space Fragmentation

Author(s): Patrycja Łydżba, Peter Prelovšek, and Marcin Mierzejewski

Hilbert space fragmentation is an ergodicity-breaking phenomenon, in which the Hamiltonian shatters into exponentially many dynamically disconnected sectors. In many fragmented systems, these sectors can be labeled by statistically localized integrals of motion, which are nonlocal operators. We stud…


[Phys. Rev. Lett. 132, 220405] Published Fri May 31, 2024

Categories: Journals, Physics

Fewer Measurements from Shadow Tomography with $N$-Representability Conditions

Author(s): Irma Avdic and David A. Mazziotti

Classical shadow tomography provides a randomized scheme for approximating the quantum state and its properties at reduced computational cost with applications in quantum computing. In this Letter we present an algorithm for realizing fewer measurements in the shadow tomography of many-body systems.…


[Phys. Rev. Lett. 132, 220802] Published Fri May 31, 2024

Categories: Journals, Physics

How to Charge Up a Sliding Water Drop

APS Physics - Fri, 2024-05-31 12:00

Author(s): Elizabeth Fernandez

Experiments and theory explain how charge builds up in a moving water drop and why the effect requires a water-repelling surface.


[Physics 17, 91] Published Fri May 31, 2024

Categories: Physics

Coherence quantifier based on the quantum optimal transport cost

PRA: Quantum information - Fri, 2024-05-31 12:00

Author(s): Xian Shi

In this work, we present a coherence measure based on the quantum optimal transport cost in terms of the convex roof extended method. We also obtain the analytical solutions of the quantifier for pure states. We also propose an operational interpretation of the coherence measure for pure states.


[Phys. Rev. A 109, 052443] Published Fri May 31, 2024

Categories: Journals, Physics

Semi-Device-Independently Characterizing Quantum Temporal Correlations

Author(s): Shin-Liang Chen and Jens Eisert

We develop a framework for characterizing quantum temporal correlations in a general temporal scenario, in which an initial quantum state is measured, sent through a quantum channel, and finally measured again. This framework does not make any assumptions on the system nor on the measurements, namel…


[Phys. Rev. Lett. 132, 220201] Published Thu May 30, 2024

Categories: Journals, Physics

Reservoir-Free Decoherence in Flying Qubits

Author(s): Nicolò Piccione, Léa Bresque, Andrew N. Jordan, Robert S. Whitney, and Alexia Auffèves

An effective time-dependent Hamiltonian can be implemented by making a quantum system fly through an inhomogeneous potential, realizing, for example, a quantum gate on its internal degrees of freedom. However, flying systems have a spatial spread that will generically entangle the internal and spati…


[Phys. Rev. Lett. 132, 220403] Published Thu May 30, 2024

Categories: Journals, Physics

Spider-Inspired Microphone Detects Tiny Gusts of Sound

APS Physics - Thu, 2024-05-30 12:00

Author(s): Rachel Berkowitz

A small device senses sounds using a spiderweb-like design—a strategy that could lead to chip-size microphones that are less affected by thermal noise.


[Physics 17, 89] Published Thu May 30, 2024

Categories: Physics

Recipe for a One-Way Waveguide

APS Physics - Thu, 2024-05-30 12:00

Author(s): Martin Rodriguez-Vega

Experiments and numerical simulations indicate that randomly replacing a few nonmagnetic components with magnetic ones in a photonic alloy induces backscattering-free light propagation along its edge.


[Physics 17, s60] Published Thu May 30, 2024

Categories: Physics

Optimal joint cutting of two-qubit rotation gates

PRA: Quantum information - Thu, 2024-05-30 12:00

Author(s): Christian Ufrecht, Laura S. Herzog, Daniel D. Scherer, Maniraman Periyasamy, Sebastian Rietsch, Axel Plinge, and Christopher Mutschler

Circuit cutting, the partitioning of quantum circuits into smaller independent fragments, has become a promising avenue for scaling up current quantum-computing experiments. Here, we introduce a scheme for joint cutting of two-qubit rotation gates based on a virtual gate-teleportation protocol. With…


[Phys. Rev. A 109, 052440] Published Thu May 30, 2024

Categories: Journals, Physics

Solving various NP-hard problems using exponentially fewer qubits on a quantum computer

PRA: Quantum information - Thu, 2024-05-30 12:00

Author(s): Yagnik Chatterjee, Eric Bourreau, and Marko J. Rančić

NP-hard problems are not believed to be exactly solvable through general polynomial time algorithms. Hybrid quantum-classical algorithms to address such combinatorial problems have been of great interest in the past few years. Such algorithms are heuristic in nature and aim to obtain an approximate …


[Phys. Rev. A 109, 052441] Published Thu May 30, 2024

Categories: Journals, Physics

Decoy-state quantum-key-distribution-based quantum private query with error tolerance bound

PRA: Quantum information - Thu, 2024-05-30 12:00

Author(s): Bin Liu, Zhonghao Liang, Wei Huang, Fei Gao, Jiayi Yuan, and Bingjie Xu

Quantum private query (QPQ) faces many challenges in practical applications. At present, some scholars have made substantial work on overcoming channel loss, channel noise, and nonideal light sources, respectively. However, a protocol that would overcome all three of these problems has yet to materi…


[Phys. Rev. A 109, 052442] Published Thu May 30, 2024

Categories: Journals, Physics
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