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Fourier Quantum Process Tomography npj Quantum Inform. (IF 7.6) Pub Date : 2024-05-09 Francesco Di Colandrea, Nazanin Dehghan, Alessio D’Errico, Ebrahim Karimi
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Minimal-noise estimation of noncommuting rotations of a spin Quantum (IF 6.4) Pub Date : 2024-05-08 Jakub Czartowski, Karol Życzkowski, Daniel Braun
We propose an analogue of $\text{SU}(1,1)$ interferometry to measure rotation of a spin by using two-spin squeezed states. Attainability of the Heisenberg limit for the estimation of the rotation angle is demonstrated for maximal squeezing. For a specific direction and strength an advantage in sensitivity for $all$ equatorial rotation axes (and hence non-commuting rotations) over the classical bound
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On the relevance of weak measurements in dissipative quantum systems Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-09 Lorena Ballesteros Ferraz, John Martin, Yves Caudano
We investigate the impact of dissipation, including energy relaxation and decoherence, on weak measurements. While weak measurements have been successful in signal amplification, dissipation can compromise their usefulness. More precisely, we show that in systems with a unique steady state, weak values always converge to an expectation value of the measured observable as dissipation time tends to infinity
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Tensor network decompositions for absolutely maximally entangled states Quantum (IF 6.4) Pub Date : 2024-05-08 Balázs Pozsgay, Ian M. Wanless
Absolutely maximally entangled (AME) states of $k$ qudits (also known as perfect tensors) are quantum states that have maximal entanglement for all possible bipartitions of the sites/parties. We consider the problem of whether such states can be decomposed into a tensor network with a small number of tensors, such that all physical and all auxiliary spaces have the same dimension $D$. We find that
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Introduction to Haar Measure Tools in Quantum Information: A Beginner’s Tutorial Quantum (IF 6.4) Pub Date : 2024-05-08 Antonio Anna Mele
The Haar measure plays a vital role in quantum information, but its study often requires a deep understanding of representation theory, posing a challenge for beginners. This tutorial aims to provide a basic introduction to Haar measure tools in quantum information, utilizing only basic knowledge of linear algebra and thus aiming to make this topic more accessible. The tutorial begins by introducing
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Privacy-preserving quantum federated learning via gradient hiding Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-08 Changhao Li, Niraj Kumar, Zhixin Song, Shouvanik Chakrabarti, Marco Pistoia
Distributed quantum computing, particularly distributed quantum machine learning, has gained substantial prominence for its capacity to harness the collective power of distributed quantum resources, transcending the limitations of individual quantum nodes. Meanwhile, the critical concern of privacy within distributed computing protocols remains a significant challenge, particularly in standard classical
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Relational superposition measurements with a material quantum ruler Quantum (IF 6.4) Pub Date : 2024-05-06 Hui Wang, Flaminia Giacomini, Franco Nori, Miles P. Blencowe
In physics, it is crucial to identify operational measurement procedures to give physical meaning to abstract quantities. There has been significant effort to define time operationally using quantum systems, but the same has not been achieved for space. Developing an operational procedure to obtain information about the location of a quantum system is particularly important for a theory combining general
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Energy conservation and fluctuation theorem are incompatible for quantum work Quantum (IF 6.4) Pub Date : 2024-05-06 Karen V. Hovhannisyan, Alberto Imparato
Characterizing fluctuations of work in coherent quantum systems is notoriously problematic. Here we reveal the ultimate source of the problem by proving that ($\mathfrak{A}$) energy conservation and ($\mathfrak{B}$) the Jarzynski fluctuation theorem cannot be observed at the same time. Condition $\mathfrak{A}$ stipulates that, for any initial state of the system, the measured average work must be equal
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Robust sparse IQP sampling in constant depth Quantum (IF 6.4) Pub Date : 2024-05-06 Louis Paletta, Anthony Leverrier, Alain Sarlette, Mazyar Mirrahimi, Christophe Vuillot
Between NISQ (noisy intermediate scale quantum) approaches without any proof of robust quantum advantage and fully fault-tolerant quantum computation, we propose a scheme to achieve a provable superpolynomial quantum advantage (under some widely accepted complexity conjectures) that is robust to noise with minimal error correction requirements. We choose a class of sampling problems with commuting
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Quantum time dilation in a gravitational field Quantum (IF 6.4) Pub Date : 2024-05-07 Jerzy Paczos, Kacper Dębski, Piotr T. Grochowski, Alexander R. H. Smith, Andrzej Dragan
According to relativity, the reading of an ideal clock is interpreted as the elapsed proper time along its classical trajectory through spacetime. In contrast, quantum theory allows the association of many simultaneous trajectories with a single quantum clock, each weighted appropriately. Here, we investigate how the superposition principle affects the gravitational time dilation observed by a simple
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Non-Markovian quantum gate set tomography Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-07 Ze-Tong Li, Cong-Cong Zheng, Fan-Xu Meng, Han Zeng, Tian Luan, Zai-Chen Zhang, Xu-Tao Yu
Engineering quantum devices requires reliable characterization of the quantum system, including qubits, quantum operations (also known as instruments) and the quantum noise. Recently, quantum gate set tomography (GST) has emerged as a powerful technique for self-consistently describing quantum states, gates, and measurements. However, non-Markovian correlations between the quantum system and environment
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Information flow in parameterized quantum circuits Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-07 Abhinav Anand, Lasse Bjørn Kristensen, Felix Frohnert, Sukin Sim, Alán Aspuru-Guzik
In this work, we introduce a new way to quantify information flow in quantum systems, especially for parameterized quantum circuits (PQCs). We use a graph representation of the circuits and propose a new distance metric using the mutual information between gate nodes. We then present an optimization procedure for variational algorithms using paths based on the distance measure. We explore the features
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Quantum thermodynamics of boundary time-crystals Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-07 Federico Carollo, Igor Lesanovsky, Mauro Antezza, Gabriele De Chiara
Time-translation symmetry breaking is a mechanism for the emergence of non-stationary many-body phases, so-called time-crystals, in Markovian open quantum systems. Dynamical aspects of time-crystals have been extensively explored over the recent years. However, much less is known about their thermodynamic properties, also due to the intrinsic nonequilibrium nature of these phases. Here, we consider
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Quantum Fourier networks for solving parametric PDEs Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-07 Nishant Jain, Jonas Landman, Natansh Mathur, Iordanis Kerenidis
Many real-world problems, like modelling environment dynamics, physical processes, time series etc involve solving partial differential equations (PDEs) parameterised by problem-specific conditions. Recently, a deep learning architecture called Fourier neural operator (FNO) proved to be capable of learning solutions of given PDE families for any initial conditions as input. However, it results in a
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Engineering holography with stabilizer graph codes npj Quantum Inform. (IF 7.6) Pub Date : 2024-05-03 Gerard Anglès Munné, Valentin Kasper, Felix Huber
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Trapping Ba+ with seven-fold enhanced efficiency utilizing an autoionizing resonance Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-03 Noah Greenberg, Brendan M White, Pei Jiang Low, Crystal Senko
Trapped ions have emerged as a front runner in quantum information processing due to their identical nature, all-to-all connectivity, and high fidelity quantum operations. As current trapped ion technologies are scaled, it will be important to improve the efficiency of loading ions, especially when working with long chains of ions or rare isotopes. Here, we compare two different isotope-selective photoionization
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Near-term distributed quantum computation using mean-field corrections and auxiliary qubits Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-03 Abigail McClain Gomez, Taylor L Patti, Anima Anandkumar, Susanne F Yelin
Distributed quantum computation is often proposed to increase the scalability of quantum hardware, as it reduces cooperative noise and requisite connectivity by sharing quantum information between distant quantum devices. However, such exchange of quantum information itself poses unique engineering challenges, requiring high gate fidelity and costly non-local operations. To mitigate this, we propose
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A hybrid quantum ensemble learning model for malicious code detection Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-05-03 Qibing Xiong, Xiaodong Ding, Yangyang Fei, Xin Zhou, Qiming Du, Congcong Feng, Zheng Shan
Quantum computing as a new computing model with parallel computing capability and high information carrying capacity, has attracted a lot of attention from researchers. Ensemble learning is an effective strategy often used in machine learning to improve the performance of weak classifiers. Currently, the classification performance of quantum classifiers is not satisfactory enough due to factors such
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Characterising the Hierarchy of Multi-time Quantum Processes with Classical Memory Quantum (IF 6.4) Pub Date : 2024-05-02 Philip Taranto, Marco Túlio Quintino, Mio Murao, Simon Milz
Memory is the fundamental form of temporal complexity: when present but uncontrollable, it manifests as non-Markovian noise; conversely, if controllable, memory can be a powerful resource for information processing. Memory effects arise from/are transmitted via interactions between a system and its environment; as such, they can be either classical or quantum. From a practical standpoint, quantum processes
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Entanglement-assisted Quantum Reed-Muller Tensor Product Codes Quantum (IF 6.4) Pub Date : 2024-05-02 Priya J. Nadkarni, Praveen Jayakumar, Arpit Behera, Shayan Srinivasa Garani
We present the construction of standard entanglement-assisted (EA) qubit Reed-Muller (RM) codes and their tensor product variants from classical RM codes. We show that the EA RM codes obtained using the CSS construction have zero coding rate and negative catalytic rate. We further show that EA codes constructed from these same classical RM codes using the tensor product code (TPC) construction have
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Quantum copy-protection of compute-and-compare programs in the quantum random oracle model Quantum (IF 6.4) Pub Date : 2024-05-02 Andrea Coladangelo, Christian Majenz, Alexander Poremba
Copy-protection allows a software distributor to encode a program in such a way that it can be evaluated on any input, yet it cannot be "pirated" – a notion that is impossible to achieve in a classical setting. Aaronson (CCC 2009) initiated the formal study of quantum copy-protection schemes, and speculated that quantum cryptography could offer a solution to the problem thanks to the quantum no-cloning
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A generic quantum Wielandt’s inequality Quantum (IF 6.4) Pub Date : 2024-05-02 Yifan Jia, Angela Capel
Quantum Wielandt's inequality gives an optimal upper bound on the minimal length $k$ such that length-$k$ products of elements in a generating system span $M_n(\mathbb{C})$. It is conjectured that $k$ should be of order $\mathcal{O}(n^2)$ in general. In this paper, we give an overview of how the question has been studied in the literature so far and its relation to a classical question in linear algebra
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Certifying long-range quantum correlations through routed Bell tests Quantum (IF 6.4) Pub Date : 2024-05-02 Edwin Peter Lobo, Jef Pauwels, Stefano Pironio
Losses in the transmission channel, which increase with distance, pose a major obstacle to photonics demonstrations of quantum nonlocality and its applications. Recently, Chaturvedi, Viola, and Pawlowski (CVP) [arXiv:2211.14231] introduced a variation of standard Bell experiments with the goal of extending the range over which quantum nonlocality can be demonstrated. These experiments, which we call
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Custom Bell inequalities from formal sums of squares Quantum (IF 6.4) Pub Date : 2024-05-02 Victor Barizien, Pavel Sekatski, Jean-Daniel Bancal
Bell inequalities play a key role in certifying quantum properties for device-independent quantum information protocols. It is still a major challenge, however, to devise Bell inequalities tailored for an arbitrary given quantum state. Existing approaches based on sums of squares provide results in this direction, but they are restricted by the necessity of first choosing measurement settings suited
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Check-Agnosia based Post-Processor for Message-Passing Decoding of Quantum LDPC Codes Quantum (IF 6.4) Pub Date : 2024-05-02 Julien du Crest, Francisco Garcia-Herrero, Mehdi Mhalla, Valentin Savin, Javier Valls
The inherent degeneracy of quantum low-density parity-check codes poses a challenge to their decoding, as it significantly degrades the error-correction performance of classical message-passing decoders. To improve their performance, a post-processing algorithm is usually employed. To narrow the gap between algorithmic solutions and hardware limitations, we introduce a new post-processing algorithm
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Spatially correlated classical and quantum noise in driven qubits npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-30 Ji Zou, Stefano Bosco, Daniel Loss
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Resource analysis for quantum-aided Byzantine agreement with the four-qubit singlet state Quantum (IF 6.4) Pub Date : 2024-04-30 Zoltán Guba, István Finta, Ákos Budai, Lóránt Farkas, Zoltán Zimborás, András Pályi
In distributed computing, a Byzantine fault is a condition where a component behaves inconsistently, showing different symptoms to different components of the system. Consensus among the correct components can be reached by appropriately crafted communication protocols even in the presence of byzantine faults. Quantum-aided protocols built upon distributed entangled quantum states are worth considering
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Complexity of Supersymmetric Systems and the Cohomology Problem Quantum (IF 6.4) Pub Date : 2024-04-30 Chris Cade, P. Marcos Crichigno
We consider the complexity of the local Hamiltonian problem in the context of fermionic Hamiltonians with $\mathcal N=2 $ supersymmetry and show that the problem remains $\mathsf{QMA}$-complete. Our main motivation for studying this is the well-known fact that the ground state energy of a supersymmetric system is exactly zero if and only if a certain cohomology group is nontrivial. This opens the door
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Metrology and multipartite entanglement in measurement-induced phase transition Quantum (IF 6.4) Pub Date : 2024-04-30 Giovanni Di Fresco, Bernardo Spagnolo, Davide Valenti, Angelo Carollo
Measurement-induced phase transition arises from the competition between a deterministic quantum evolution and a repeated measurement process. We explore the measurement-induced phase transition through the Quantum Fisher Information in two different metrological scenarios. We demonstrate through the scaling behavior of the quantum Fisher information the transition of the multi-partite entanglement
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Low-depth simulations of fermionic systems on square-grid quantum hardware Quantum (IF 6.4) Pub Date : 2024-04-30 Manuel G. Algaba, P. V. Sriluckshmy, Martin Leib, Fedor Šimkovic IV
We present a general strategy for mapping fermionic systems to quantum hardware with square qubit connectivity which yields low-depth quantum circuits, counted in the number of native two-qubit fSIM gates. We achieve this by leveraging novel operator decomposition and circuit compression techniques paired with specifically chosen low-depth fermion-to-qubit mappings and allow for a high degree of gate
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Hunting for quantum-classical crossover in condensed matter problems npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-29 Nobuyuki Yoshioka, Tsuyoshi Okubo, Yasunari Suzuki, Yuki Koizumi, Wataru Mizukami
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Photonic entanglement with accelerated light Quantum (IF 6.4) Pub Date : 2024-04-30 R. C. Souza Pimenta, G. H. dos Santos, A. B. Barreto, L. C. Celeri, P. H. Souto Ribeiro
Accelerated light has been demonstrated with laser light and diffraction. Within the diffracting field it is possible to identify a portion that carries most of the beam energy, which propagates in a curved trajectory as it would have been accelerated by a gravitational field for instance. Here, we analyze the effects of this kind of acceleration over the entanglement between twin beams produced in
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Mutually unbiased bases: polynomial optimization and symmetry Quantum (IF 6.4) Pub Date : 2024-04-30 Sander Gribling, Sven Polak
A set of $k$ orthonormal bases of $\mathbb C^d$ is called mutually unbiased if $|\langle e,f\rangle |^2 = 1/d$ whenever $e$ and $f$ are basis vectors in distinct bases. A natural question is for which pairs $(d,k)$ there exist $k$ mutually unbiased bases in dimension $d$. The (well-known) upper bound $k \leq d+1$ is attained when $d$ is a power of a prime. For all other dimensions it is an open problem
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Learning quantum many-body systems from a few copies Quantum (IF 6.4) Pub Date : 2024-04-30 Cambyse Rouzé, Daniel Stilck França
Estimating physical properties of quantum states from measurements is one of the most fundamental tasks in quantum science. In this work, we identify conditions on states under which it is possible to infer the expectation values of all quasi-local observables of a state from a number of copies that scales polylogarithmically with the system's size and polynomially on the locality of the target observables
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Approximating quantum channels by completely positive maps with small Kraus rank Quantum (IF 6.4) Pub Date : 2024-04-30 Cécilia Lancien, Andreas Winter
We study the problem of approximating a quantum channel by one with as few Kraus operators as possible (in the sense that, for any input state, the output states of the two channels should be close to one another). Our main result is that any quantum channel mapping states on some input Hilbert space $\mathrm{A}$ to states on some output Hilbert space $\mathrm{B}$ can be compressed into one with order
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A family of permutationally invariant quantum codes Quantum (IF 6.4) Pub Date : 2024-04-30 Arda Aydin, Max A. Alekseyev, Alexander Barg
We construct a new family of permutationally invariant codes that correct $t$ Pauli errors for any $t\ge 1$. We also show that codes in the new family correct quantum deletion errors as well as spontaneous decay errors. Our construction contains some of the previously known permutationally invariant quantum codes as particular cases, which also admit transversal gates. In many cases, the codes in the
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Derivative Pricing using Quantum Signal Processing Quantum (IF 6.4) Pub Date : 2024-04-30 Nikitas Stamatopoulos, William J. Zeng
Pricing financial derivatives on quantum computers typically includes quantum arithmetic components which contribute heavily to the quantum resources required by the corresponding circuits. In this manuscript, we introduce a method based on Quantum Signal Processing (QSP) to encode financial derivative payoffs directly into quantum amplitudes, alleviating the quantum circuits from the burden of costly
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Hidden variable model for quantum computation with magic states on qudits of any dimension Quantum (IF 6.4) Pub Date : 2024-04-30 Michael Zurel, Cihan Okay, Robert Raussendorf, Arne Heimendahl
It was recently shown that a hidden variable model can be constructed for universal quantum computation with magic states on qubits. Here we show that this result can be extended, and a hidden variable model can be defined for quantum computation with magic states on qudits with any Hilbert space dimension. This model leads to a classical simulation algorithm for universal quantum computation.
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Operational Markovianization in randomized benchmarking Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-30 P Figueroa-Romero, M Papič, A Auer, M-H Hsieh, K Modi, I de Vega
A crucial task to obtain optimal and reliable quantum devices is to quantify their overall performance. The average fidelity of quantum gates is a particular figure of merit that can be estimated efficiently by randomized benchmarking (RB). However, the concept of gate-fidelity itself relies on the crucial assumption that noise behaves in a predictable, time-local, or so-called Markovian manner, whose
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Optimal quantum key distribution networks: capacitance versus security npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-29 Lorenzo Cirigliano, Valentina Brosco, Claudio Castellano, Claudio Conti, Laura Pilozzi
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Structural transitions, octahedral rotations, and electronic properties of A3Ni2O7 rare-earth nickelates under high pressure npj Quant. Mater. (IF 5.7) Pub Date : 2024-04-26 Benjamin Geisler, James J. Hamlin, Gregory R. Stewart, Richard G. Hennig, P. J. Hirschfeld
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Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-26 Mustafa Bal, Akshay A. Murthy, Shaojiang Zhu, Francesco Crisa, Xinyuan You, Ziwen Huang, Tanay Roy, Jaeyel Lee, David van Zanten, Roman Pilipenko, Ivan Nekrashevich, Andrei Lunin, Daniel Bafia, Yulia Krasnikova, Cameron J. Kopas, Ella O. Lachman, Duncan Miller, Josh Y. Mutus, Matthew J. Reagor, Hilal Cansizoglu, Jayss Marshall, David P. Pappas, Kim Vu, Kameshwar Yadavalli, Jin-Su Oh, Lin Zhou, Matthew
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Parameter estimation from quantum-jump data using neural networks Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-26 Enrico Rinaldi, Manuel González Lastre, Sergio García Herreros, Shahnawaz Ahmed, Maryam Khanahmadi, Franco Nori, Carlos Sánchez Muñoz
We present an inference method utilizing artificial neural networks for parameter estimation of a quantum probe monitored through a single continuous measurement. Unlike existing approaches focusing on the diffusive signals generated by continuous weak measurements, our method harnesses quantum correlations in discrete photon-counting data characterized by quantum jumps. We benchmark the precision
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Modelling non-Markovian noise in driven superconducting qubits Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-26 Abhishek Agarwal, Lachlan P Lindoy, Deep Lall, François Jamet, Ivan Rungger
Non-Markovian noise can be a significant source of errors in superconducting qubits. We develop gate sequences utilising mirrored pseudoidentities that allow us to characterise and model the effects of non-Markovian noise on both idle and driven qubits. We compare three approaches to modelling the observed noise: (i) a Markovian noise model, (ii) a model including interactions with a two-level system
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An optically pumped magnetic gradiometer for the detection of human biomagnetism Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-26 Harry Cook, Yulia Bezsudnova, Lari M Koponen, Ole Jensen, Giovanni Barontini, Anna U Kowalczyk
We realise an intrinsic optically pumped magnetic gradiometer based on non-linear magneto-optical rotation. We show that our sensor can reach a gradiometric sensitivity of 18 fT cm−1Hz−1 and can reject common mode homogeneous magnetic field noise with up to 30 dB attenuation. We demonstrate that our magnetic field gradiometer is sufficiently sensitive and resilient to be employed in biomagnetic applications
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Bilayer ion trap design for 2D arrays Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-26 Gavin N Nop, Jonathan D H Smith, Daniel Stick, Durga Paudyal
Junctions are fundamental elements that support qubit locomotion in two-dimensional ion trap arrays and enhance connectivity in emerging trapped-ion quantum computers. In surface ion traps they have typically been implemented by shaping radio frequency (RF) electrodes in a single plane to minimize the disturbance to the pseudopotential. However, this method introduces issues related to RF lead routing
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Topologically protected subradiant cavity polaritons through linewidth narrowing enabled by dissipationless edge states Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-26 Yu-Wei Lu, Jing-Feng Liu, Haoxiang Jiang, Zeyang Liao
Cavity polaritons derived from strong light–matter interaction provide a basis for efficient manipulation of quantum states via cavity field. Polaritons with narrow linewidth and long lifetime are appealing in applications, such as quantum sensing and storage. Here, we propose a prototypical arrangement to implement a whispering-gallery-mode resonator with one-dimensional topological atom mirror, which
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Efficient quantum algorithm for all quantum wavelet transforms Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-21 Mohsen Bagherimehrab and Alán Aspuru-Guzik
Wavelet transforms are widely used in various fields of science and engineering as a mathematical tool with features that reveal information ignored by the Fourier transform. Unlike the Fourier transform, which is unique, a wavelet transform is specified by a sequence of numbers associated with the type of wavelet used and an order parameter specifying the length of the sequence. While the quantum
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Ten principles for responsible quantum innovation Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-21 Mauritz Kop, Mateo Aboy, Eline De Jong, Urs Gasser, Timo Minssen, I Glenn Cohen, Mark Brongersma, Teresa Quintel, Luciano Floridi and Raymond Laflamme
This paper proposes a set of guiding principles for responsible quantum innovation. The principles are organized into three functional categories: safeguarding, engaging, and advancing (SEA), and are linked to central values in responsible research and innovation (RRI). Utilizing a global equity normative framework and literature-based methodology, we connect the quantum-SEA categories to promise and
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Neural-network-designed three-qubit gates robust against charge noise and crosstalk in silicon Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-21 David W Kanaar and J P Kestner
Spin qubits in semiconductor quantum dots are a promising platform for quantum computing, however, scaling to large systems is hampered by crosstalk and charge noise. Crosstalk here refers to the unwanted off-resonant rotation of idle qubits during the resonant rotation of the target qubit. For a three-qubit system with crosstalk and charge noise, it is difficult to analytically create gate protocols
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Quantum Davidson algorithm for excited states Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-21 Nikolay V Tkachenko, Lukasz Cincio, Alexander I Boldyrev, Sergei Tretiak, Pavel A Dub and Yu Zhang
Excited state properties play a pivotal role in various chemical and physical phenomena, such as charge separation and light emission. However, the primary focus of most existing quantum algorithms has been the ground state, as seen in quantum phase estimation and the variational quantum eigensolver (VQE). Although VQE-type methods have been extended to explore excited states, these methods grapple
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Remote cross-resonance gate between superconducting fixed-frequency qubits Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-04-25 Mari Ohfuchi, Shintaro Sato
High-fidelity quantum state transfer and remote entanglement between superconducting fixed-frequency qubits have not yet been realized. In this study, we propose an alternative remote cross-resonance gate. Considering multiple modes of a superconducting coaxial cable connecting qubits, we must find conditions under which the cross-resonance gate operates with a certain accuracy even in the presence
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Circuit complexity of quantum access models for encoding classical data npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-23 Xiao-Ming Zhang, Xiao Yuan
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Quantum sensing of magnetic fields with molecular spins npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-23 Claudio Bonizzoni, Alberto Ghirri, Fabio Santanni, Marco Affronte
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Tight Lieb–Robinson Bound for approximation ratio in quantum annealing npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-17 Arthur Braida, Simon Martiel, Ioan Todinca
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Error-mitigated fermionic classical shadows on noisy quantum devices npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-16 Bujiao Wu, Dax Enshan Koh
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Atomic-scale magnetic doping of monolayer stanene by revealing Kondo effect from self-assembled Fe spin entities npj Quant. Mater. (IF 5.7) Pub Date : 2024-04-12 Nitin Kumar, Ye-Shun Lan, Iksu Jang, Yen-Hui Lin, Chia-Ju Chen, Tzu-Hsuan Lin, Horng-Tay Jeng, Po-Yao Chang, Pin-Jui Hsu
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Entangling entanglement: coupling frequency and polarization of biphotons on demand npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-12 Arash Riazi, Eric Y. Zhu, Dan Xu, Li Qian
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Fast pseudorandom quantum state generators via inflationary quantum gates npj Quantum Inform. (IF 7.6) Pub Date : 2024-04-10 Claudio Chamon, Eduardo R. Mucciolo, Andrei E. Ruckenstein, Zhi-Cheng Yang
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Charge transfer and spin-valley locking in 4Hb-TaS2 npj Quant. Mater. (IF 5.7) Pub Date : 2024-04-10 Avior Almoalem, Roni Gofman, Yuval Nitzav, Ilay Mangel, Irena Feldman, Jahyun Koo, Federico Mazzola, Jun Fujii, Ivana Vobornik, J. S´anchez-Barriga, Oliver J. Clark, Nicholas Clark Plumb, Ming Shi, Binghai Yan, Amit Kanigel