Article
Quantum Science & Technology
Jacopo Angeletti, Stefano Zippilli, David Vitali
Summary: We study the dissipative stabilization of entangled states in arrays of quantum systems, focusing on qubits (spin-1/2) that may or may not interact with cavities (bosonic modes). When a cavity is lossy, we consider a squeezed reservoir and interactions that conserve cavity excitations. When a qubit is lossy, we take into account pure decay and a specially designed structure of XY interactions. We show that in the steady state, distant non-directly interacting qubit pairs can become entangled through the interplay of dissipation and local interactions.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Editorial Material
Physics, Multidisciplinary
Federico Levi
Summary: This article discusses what makes a good qubit.
Article
Multidisciplinary Sciences
Thomas Hartke, Botond Oreg, Ningyuan Jia, Martin Zwierlein
Summary: This study demonstrates long-lived motional coherence and entanglement of pairs of fermionic atoms in an optical lattice array, where the common and relative motion of each pair form a robust qubit. The methods presented in this research will have important applications in coherently programmable quantum simulators, precision metrology based on atom pairs and molecules, and digital quantum computation using fermion pairs.
Article
Quantum Science & Technology
Justin Yirka, Yigit Subasi
Summary: This study develops qubit-efficient quantum algorithms for entanglement spectroscopy which avoid the tradeoff between circuit width and depth, enabling spectroscopy of larger quantum systems on NISQ devices. The algorithms achieve noise-resilience by measuring and reinitializing subsets of qubits during computation, increasing circuit depth without suffering from noise consequences. The effective circuit depth concept aids in explaining the noise resilience and designing future algorithms.
Article
Physics, Multidisciplinary
Bartosz Regula
Summary: This paper presents a new resource monotone that can rule out all transformations, probabilistic or deterministic, between states in any quantum resource theory. The results obtained from this approach provide significant improvements for probabilistic distillation protocols, allowing for better error and overhead bounds. The monotone also serves as a necessary and sufficient condition for state convertibility.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Martin J. Renner, Armin Tavakoli, Marco Tulio Quintino
Summary: This article discusses the transmission of qubit states from Alice to Bob and general measurements in the form of positive operator-valued measures (POVMs). The research found that the statistics obtained in any quantum protocol can be simulated using shared randomness and only two bits of classical communication. Furthermore, it was proven that two bits of communication is the minimum cost for a perfect classical simulation. The methods were also applied to Bell scenarios, extending the well-known Toner and Bacon protocol, and demonstrating that two bits of communication are sufficient to simulate all quantum correlations associated with arbitrary local POVMs applied to any entangled two-qubit state.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Dario Lago-Rivera, Jelena V. Rakonjac, Samuele Grandi, Hugues de Riedmatten
Summary: The researchers have successfully demonstrated long-distance quantum teleportation by transferring a photonic qubit to a solid-state quantum memory. They utilized time-multiplexing to increase the teleportation rate, and the system is compatible with existing telecommunication networks. This achievement is significant for the development of long-distance quantum communication.
NATURE COMMUNICATIONS
(2023)
Article
Quantum Science & Technology
Cheng-Chen Luo, Lan Zhou, Wei Zhong, Yu-Bo Sheng
Summary: This paper presents a hybrid logical qubit entanglement purification protocol that can extract a high-quality copy from low-quality copies. The protocol can purify bit-flip errors occurring in the polarization part, the coherent state part, and the logical qubit, and it can also work in the photon loss condition.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Multidisciplinary Sciences
Andrei Ruskuc, Chun-Ju Wu, Jake Rochman, Joonhee Choi, Andrei Faraon
Summary: Solid-state nuclear spins surrounding individual qubits have great potential for quantum networks, computation, and simulation. In this study, a highly coherent, optically addressed Yb(3+) qubit doped into a nuclear-spin-rich crystal was used to develop a robust quantum control protocol for manipulating the multi-level nuclear spin states of neighbouring lattice ions. The researchers successfully polarized the nuclear spin ensemble, generated collective spin excitations, and implemented a quantum memory using these dense nuclear spin ensembles. They also demonstrated the preparation and measurement of maximally entangled Bell states. Their deterministic and reproducible platform provides a framework for building large-scale quantum networks using single rare-earth ion qubits.
Article
Physics, Multidisciplinary
Marios Kounalakis, Gerrit E. W. Bauer, Yaroslav M. Blanter
Summary: This article proposes a method to directly and quantum-coherently couple a superconducting transmon qubit to magnons, the quanta of collective spin excitations in a nearby magnetic particle. It also demonstrates a quantum control scheme that generates high-fidelity magnon-qubit entanglement and magnonic Schr??dinger cat states.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Richard A. Brewster, Gerald Baumgartner, Yanne K. Chembo
Summary: A general technique is introduced to experimentally characterize the effect of qubit-preserving impairments on the Clauser-Horne-Shimony-Holt parameter. This technique is independent of the qubit encoding and is theoretically demonstrated for specific impairments in polarization-encoded quantum-optical qubits. The analysis also includes the incorporation of spectrotemporal impairments into this technique.
Article
Quantum Science & Technology
Bartosz Rzepkowski, Katarzyna Roszak
Summary: A scheme for detecting qubit-environment entanglement is proposed, which only requires operations and measurements on the qubit and works for any type of interaction leading to pure dephasing, as long as the initial qubit state is pure. The detection can be done at a certain time tau after the qubit initialization in a superposition state, by comparing the post-measurement evolution to a modified evolution scheme.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Physics, Multidisciplinary
Y. Mei, Y. Li, H. Nguyen, P. R. Berman, A. Kuzmich
Summary: Researchers have created a special two-level system in an ensemble of several hundred atoms and observed oscillations between the ground state and collective Rydberg state. They have also obtained the light shifts of the qubits using interference techniques and derived an effective two-level model that agrees well with their observations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Swati Kumari, Javid Naikoo, Sibasish Ghosh, A. K. Pan
Summary: Incompatibility and nonlocality play important roles not only in foundational research but also in quantum information theory. The study investigates these concepts in qubit channels. The research shows that the incompatibility of a channel's conjugate is equivalent to the nonlocality breaking of the channel and vice versa in the Bell-CHSH scenario. However, this equivalence does not straightforwardly extend to multipartite systems. The study explores the relation between incompatibility and nonlocality in the tripartite scenario and identifies the coexistence of incompatibility and nonlocality in certain state and channel parameters. Additionally, a set of unital qubit channels is identified that breaks Mermin or Svetlichny nonlocality regardless of the input state.
Article
Quantum Science & Technology
Simon J. D. Phoenix, Faisal Shah Khan, Berihu Teklu
Summary: The production and manipulation of quantum correlation protocols is an active area of research, where the quantum nature of the correlation can be used to achieve properties unattainable in a classical framework. This work focuses on measuring the strength of correlation between quantum systems, with a special emphasis on multipartite systems.
QUANTUM INFORMATION PROCESSING
(2021)