Yu-Ao Chen, Xia Liu, Chenghong Zhu, Lei Zhang, Junyu Liu, Xin Wang
{"title":"Quantum Entanglement Allocation through a Central Hub","authors":"Yu-Ao Chen, Xia Liu, Chenghong Zhu, Lei Zhang, Junyu Liu, Xin Wang","doi":"arxiv-2409.08173","DOIUrl":"https://doi.org/arxiv-2409.08173","url":null,"abstract":"Establishing a fully functional quantum internet relies on the efficient\u0000allocation of multipartite entangled states, which enables advanced quantum\u0000communication protocols, secure multipartite quantum key distribution, and\u0000distributed quantum computing. In this work, we propose local operations and\u0000classical communication (LOCC) protocols for allocating generalized $N$-qubit W\u0000and GHZ states within a centralized hub architecture, where the central hub\u0000node preshares Bell states with each end node. Our protocols deterministically\u0000and exactly distribute these states using only $N$ qubits of quantum memory\u0000within the central system, with communication costs of $2N - 2$ and $N$\u0000classical bits for W and GHZ states, respectively. These resource-efficient\u0000protocols are further proven to be optimal within the centralized hub\u0000architecture, outperforming conventional teleportation protocols for\u0000entanglement distribution in both memory and communication costs. Our results\u0000provide a more resource-efficient method for allocating essential multipartite\u0000entangled states in quantum networks, paving the way for the realization of a\u0000quantum internet with enhanced efficiency.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Demonstration of Scully-Drühl-type quantum erasers on quantum computers","authors":"Bo-Hung Chen, Dah-Wei Chiou, Hsiu-Chuan Hsu","doi":"arxiv-2409.08053","DOIUrl":"https://doi.org/arxiv-2409.08053","url":null,"abstract":"We present a novel quantum circuit that genuinely implements the\u0000Scully-Dr\"uhl-type delayed-choice quantum eraser, where the two recorders of\u0000the which-way information directly interact with the signal qubit and remain\u0000spatially separated. Experiments conducted on IBM Quantum and IonQ processors\u0000demonstrate that the recovery of interference patterns, to varying degrees,\u0000aligns closely with theoretical predictions, despite the presence of systematic\u0000errors. This quantum circuit-based approach, more manageable and versatile than\u0000traditional optical experiments, facilitates arbitrary adjustment of the\u0000erasure and enables a true random choice in a genuine delayed-choice manner. On\u0000the IBM Quantum platform, delay gates can be employed to further defer the\u0000random choice, thereby amplifying the retrocausal effect. Since gate operations\u0000are executed sequentially in time, the system does not have any involvement of\u0000random choice until after the signal qubit has been measured, therefore\u0000eliminating any potential philosophical loopholes regarding retrocausality that\u0000might exist in other experimental setups. Remarkably, quantum erasure is\u0000achieved with delay times up to $sim1,mutext{s}$ without noticeable\u0000decoherence, a feat challenging to replicate in optical setups.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ming-Zhi Chung, Andreas Thomasen, Henry Liao, Ryosuke Imai
{"title":"Contrasting Statistical Phase Estimation with the Variational Quantum Eigensolver in the era of Early Fault Tolerant Quantum Computation","authors":"Ming-Zhi Chung, Andreas Thomasen, Henry Liao, Ryosuke Imai","doi":"arxiv-2409.07749","DOIUrl":"https://doi.org/arxiv-2409.07749","url":null,"abstract":"In this review, we give an overview of the proposed applications in the\u0000early-FTQC (EFTQC) era. Starting from the error correction architecture for EFTQC device, we first\u0000review the recently developed space-time efficient analogue rotation (STAR)\u0000architecture cite{akahoshiPartiallyFaultTolerantQuantum2024}, which is a\u0000partially fault-tolerant error correction architecture. Then, we review the requirements of an EFTQC algorithm. In particular, the class of ground state energy estimation (GSEE) algorithm\u0000known as the statistical phase estimation algorithm (SPE) is studied. We especially cast our attention on two SPE-type algorithms, the\u0000step-function filter-based variant by Lin and Tong (LT22) cite{Lin:2021rwb}\u0000and Gaussian Filter cite{Wang:2022gxu}. Based on the latter, we introduce the Gaussian Fitting algorithm, which uses\u0000an alternative post-processing procedure compared to cite{Wang:2022gxu}. Finally, we systematically simulate the aforementioned algorithms and\u0000Variational Quantum Eigensolver (VQE) using the 1-uCJ ansatz with different\u0000shot counts. Most importantly, we perform noisy simulations based on the STAR\u0000architecture. We find that for estimating the ground state energy of the 4-qubit $H_2$\u0000Hamiltonian in the STO-3G basis, SPE becomes more advantageous over VQE when\u0000the physical error rate is sufficiently low.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinbing Hu, Kai Zhou, Tianle Song, Xuntao Jiang, Songlin Zhuang, Yi Yang
{"title":"Acoustic higher-order topological insulator from momentum-space nonsymmorphic symmetries","authors":"Jinbing Hu, Kai Zhou, Tianle Song, Xuntao Jiang, Songlin Zhuang, Yi Yang","doi":"arxiv-2409.08196","DOIUrl":"https://doi.org/arxiv-2409.08196","url":null,"abstract":"Momentum-space nonsymmorphic symmetries, stemming from the projective algebra\u0000of synthetic gauge fields, can modify the manifold of the Brillouin zone and\u0000lead to a variety of topological phenomena. We present an acoustic realization\u0000of higher-order topological insulators (HOTIs) protected by a pair of\u0000anticommutative momentum-space glide reflections. We confirm the presence of\u0000momentum-space glide reflection from the measured momentum half translation of\u0000edge bands and their momentum-resolved probability distribution using a\u0000cylinder geometry made of acoustic resonator arrays. In particular, we observe\u0000both intrinsic and extrinsic HOTI features in such a cylinder: hopping strength\u0000variation along the open boundary leads to a bulk gap closure, while that along\u0000the closed boundary results in an edge gap closure. In addition, we confirm the\u0000presence of quadrupole corner modes with transmission and field distribution\u0000measurements. Our observation enriches the study of topological physics of\u0000momentum-space nonsymmorphic symmetries.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. -T. Cheng, K. -M. Hsieh, B. -Y. Wu, Z. Q. Niu, F. Aziz, Y. -H. Huang, P. Y. Wen, K. -T. Lin, Y. -H. Lin, J. C. Chen, A. F. Kockum, G. -D. Lin, Z. -R. Lin, Y. Lu, I. -C. Hoi
{"title":"Group delay controlled by the decoherence of a single artificial atom","authors":"Y. -T. Cheng, K. -M. Hsieh, B. -Y. Wu, Z. Q. Niu, F. Aziz, Y. -H. Huang, P. Y. Wen, K. -T. Lin, Y. -H. Lin, J. C. Chen, A. F. Kockum, G. -D. Lin, Z. -R. Lin, Y. Lu, I. -C. Hoi","doi":"arxiv-2409.07731","DOIUrl":"https://doi.org/arxiv-2409.07731","url":null,"abstract":"The ability to slow down light at the single-photon level has applications in\u0000quantum information processing and other quantum technologies. We demonstrate\u0000two methods, both using just a single artificial atom, enabling dynamic control\u0000over microwave light velocities in waveguide quantum electrodynamics (waveguide\u0000QED). Our methods are based on two distinct mechanisms harnessing the balance\u0000between radiative and non-radiative decay rates of a superconducting artificial\u0000atom in front of a mirror. In the first method, we tune the radiative decay of\u0000the atom using interference effects due to the mirror; in the second method, we\u0000pump the atom to control its non-radiative decay through the Autler--Townes\u0000effect. When the half the radiative decay rate exceeds the non-radiative decay\u0000rate, we observe positive group delay; conversely, dominance of the\u0000non-radiative decay rate results in negative group delay. Our results advance\u0000signal-processing capabilities in waveguide QED.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Annika S. Wiening, Joern Bergendahl, Vicente Leyton-Ortega, Peter Nalbach
{"title":"Optimizing Qubit Control Pulses for State Preparation","authors":"Annika S. Wiening, Joern Bergendahl, Vicente Leyton-Ortega, Peter Nalbach","doi":"arxiv-2409.08204","DOIUrl":"https://doi.org/arxiv-2409.08204","url":null,"abstract":"In the burgeoning field of quantum computing, the precise design and\u0000optimization of quantum pulses are essential for enhancing qubit operation\u0000fidelity. This study focuses on refining the pulse engineering techniques for\u0000superconducting qubits, employing a detailed analysis of Square and Gaussian\u0000pulse envelopes under various approximation schemes. We evaluated the effects\u0000of coherent errors induced by naive pulse designs. We identified the sources of\u0000these errors in the Hamiltonian model's approximation level. We mitigated these\u0000errors through adjustments to the external driving frequency and pulse\u0000durations, thus, implementing a pulse scheme with stroboscopic error reduction.\u0000Our results demonstrate that these refined pulse strategies improve performance\u0000and reduce coherent errors. Moreover, the techniques developed herein are\u0000applicable across different quantum architectures, such as ion-trap, atomic,\u0000and photonic systems.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Vision for a Bohm-Style Theory of Quantum Electrodynamics","authors":"Roderich Tumulka","doi":"arxiv-2409.07784","DOIUrl":"https://doi.org/arxiv-2409.07784","url":null,"abstract":"Despite many successes of quantum electrodynamics (QED), we do not presently\u0000have a good understanding of this field of physics. QED has all of the\u0000foundational problems that standard non-relativistic quantum mechanics has, and\u0000further ones in addition. I discuss some of these problems and some options for\u0000what a Bohm-style theory of QED, with an ontology in space and time, could look\u0000like. I also point out why the proposal made by Bohm himself in 1952 for QED is\u0000not quite convincing. Finally, I outline the kind of Bohm-type theory of QED\u0000that I would consider convincing, and report about recent progress toward this\u0000kind of theory.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco Monzani, Emanuele Ricci, Luca Nigro, Enrico Prati
{"title":"Leveraging non-unital noise for gate-based quantum reservoir computing","authors":"Francesco Monzani, Emanuele Ricci, Luca Nigro, Enrico Prati","doi":"arxiv-2409.07886","DOIUrl":"https://doi.org/arxiv-2409.07886","url":null,"abstract":"We identify a noise model that ensures the functioning of an echo state\u0000network employing a gate-based quantum computer for reservoir computing\u0000applications. Energy dissipation induced by amplitude damping drastically\u0000improves the short-term memory capacity and expressivity of the network, by\u0000simultaneously providing fading memory and richer dynamics. There is an ideal\u0000dissipation rate that ensures the best operation of the echo state network\u0000around $gammasim$ 0.03. Nevertheless, these beneficial effects are stable as\u0000the intensity of the applied noise increases. The improvement of the learning\u0000is confirmed by emulating a realistic noise model applied to superconducting\u0000qubits, paving the way for the application of reservoir computing methods in\u0000current non-fault-tolerant quantum computers.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"401 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correlated quantum machines beyond the standard second law","authors":"Milton Aguilar, Eric Lutz","doi":"arxiv-2409.07899","DOIUrl":"https://doi.org/arxiv-2409.07899","url":null,"abstract":"The laws of thermodynamics strongly restrict the performance of thermal\u0000machines. Standard thermodynamics, initially developed for uncorrelated\u0000macroscopic systems, does not hold for microscopic systems correlated with\u0000their environments. We here derive exact generalized laws of quantum\u0000thermodynamics for arbitrary, time-periodic, open systems that account for all\u0000possible correlations between all involved parties. We demonstrate the\u0000existence of two basic modes of engine operation: the usual thermal case, where\u0000heat is converted into work, and a novel athermal regime, where work is\u0000extracted from entropic resources, such as system-bath correlations. In the\u0000latter regime, the efficiency of a quantum engine is not bounded by the usual\u0000Carnot formula. Our results provide a unified formalism to determine the\u0000efficiency of correlated microscopic thermal devices.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"241 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriel Fernandez Ferrari, Łukasz Rudnicki, Lucas Chibebe Céleri
{"title":"Quantum thermodynamics as a gauge theory","authors":"Gabriel Fernandez Ferrari, Łukasz Rudnicki, Lucas Chibebe Céleri","doi":"arxiv-2409.07676","DOIUrl":"https://doi.org/arxiv-2409.07676","url":null,"abstract":"Thermodynamics is based on a coarse-grained approach, from which its\u0000fundamental variables emerge, effectively erasing the complicate details of the\u0000microscopic dynamics within a macroscopic system. The strength of\u0000Thermodynamics lies in the universality provided by this paradigm. In contrast,\u0000quantum mechanics focuses on describing the dynamics of microscopic systems,\u0000aiming to make predictions about experiments we perform, a goal shared by all\u0000fundamental physical theories, which are often framed as gauge theories in\u0000modern physics. Recently, a gauge theory for quantum thermodynamics was\u0000introduced, defining gauge invariant work and heat, and exploring their\u0000connections to quantum phenomena. In this work, we extend that theory in two\u0000significant ways. First, we incorporate energy spectrum degeneracies, which\u0000were previously overlooked. Additionally, we define gauge-invariant entropy,\u0000exploring its properties and connections to other physical and informational\u0000quantities. This results in a complete framework for quantum thermodynamics\u0000grounded in the principle of gauge invariance. To demonstrate some implications\u0000of this theory, we apply it to well-known critical systems.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}