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Scalable temporal multiplexing of telecom photons via thin-film lithium niobate photonics npj Quantum Inform. (IF 6.6) Pub Date : 2025-02-06 Çağın Ekici, Yonghe Yu, Jeremy C. Adcock, Alif Laila Muthali, Mujtaba Zahidy, Heyun Tan, Zhongjin Lin, Hao Li, Leif K. Oxenløwe, Xinlun Cai, Yunhong Ding
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Low-error encoder for time-bin and decoy states for quantum key distribution npj Quantum Inform. (IF 6.6) Pub Date : 2025-02-06 Davide Scalcon, Elisa Bazzani, Giuseppe Vallone, Paolo Villoresi, Marco Avesani
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Experimental simulation of daemonic work extraction in open quantum batteries on a digital quantum computer Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-06 Seyed Navid Elyasi, Matteo A C Rossi and Marco G Genoni
The possibility of extracting more work from a physical system thanks to the information obtained from measurements has been a topic of fundamental interest in the context of thermodynamics since the formulation of the Maxwell’s demon thought experiment. We here consider this problem from the perspective of an open quantum battery interacting with an environment that can be continuously measured. By
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Quadrature-PT symmetry: classical-to-quantum transition in noise fluctuations Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-06 Wencong Wang, Yanhua Zhai, Dongmei Liu, Xiaoshun Jiang, Saeid Vashahri Ghamsari and Jianming Wen
While gain-loss-coupled photonic platforms have achieved significant success in studying classical parity-time (PT) symmetry, they encounter challenges in demonstrating pure quantum effects due to incompatible operator transformations and Langevin noise. Here, we present compelling evidence that a non-Hermitian (NH) twin-beam system, undergoing phase-sensitive amplification and balanced loss, not only
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Asymmetric secure multi-party quantum computation with weak clients against dishonest majority Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-06 Theodoros Kapourniotis, Elham Kashefi, Dominik Leichtle, Luka Music and Harold Ollivier
Secure multi-party computation (SMPC) protocols allow several parties distrusting each other to collectively compute a function on their inputs, without revealing the input values. In this paper, we introduce a protocol that lifts SMPC to its quantum counterpart—secure multi-party quantum computation (SMPQC) for classical inputs and outputs—in a composable and statistically secure way, even for a single
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Comparative study of quantum error correction strategies for the heavy-hexagonal lattice Quantum (IF 5.1) Pub Date : 2025-02-06 César Benito, Esperanza López, Borja Peropadre, Alejandro Bermudez
Topological quantum error correction is a milestone in the scaling roadmap of quantum computers, which targets circuits with trillions of gates that would allow running quantum algorithms for real-world problems. The square-lattice surface code has become the workhorse to address this challenge, as it poses milder requirements on current devices both in terms of required error rates and small local
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Enhancing Scalability of Quantum Eigenvalue Transformation of Unitary Matrices for Ground State Preparation through Adaptive Finer Filtering Quantum (IF 5.1) Pub Date : 2025-02-06 Erenay Karacan, Yanbin Chen, Christian B. Mendl
Hamiltonian simulation is a domain where quantum computers have the potential to outperform their classical counterparts. One of the main challenges of such quantum algorithms is increasing the system size, which is necessary to achieve meaningful quantum advantage. In this work, we present an approach to improve the scalability of eigenspace filtering for the ground state preparation of a given Hamiltonian
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Metrological Advantages in Seeded and Lossy Nonlinear Interferometers Quantum (IF 5.1) Pub Date : 2025-02-04 Jasper Kranias, Guillaume Thekkadath, Khabat Heshami, Aaron Z. Goldberg
The quantum Fisher information (QFI) bounds the sensitivity of a quantum measurement, heralding the conditions for quantum advantages when compared with classical strategies. Here, we calculate analytical expressions for the QFI of nonlinear interferometers under lossy conditions and with coherent-state seeding. We normalize the results based on the number of photons going through the sample that induces
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Low-Rank Variational Quantum Algorithm for the Dynamics of Open Quantum Systems Quantum (IF 5.1) Pub Date : 2025-02-04 Sara Santos, Xinyu Song, Vincenzo Savona
The simulation of many-body open quantum systems is key to solving numerous outstanding problems in physics, chemistry, material science, and in the development of quantum technologies. Near-term quantum computers may bring considerable advantage for the efficient simulation of their static and dynamical properties, thanks to hybrid quantum-classical variational algorithms to approximate the dynamics
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Theory of Multimode Squeezed Light Generation in Lossy Media Quantum (IF 5.1) Pub Date : 2025-02-04 Denis A. Kopylov, Torsten Meier, Polina R. Sharapova
A unified theoretical approach to describe the properties of multimode squeezed light generated in a lossy medium is presented. This approach is valid for Markovian environments and includes both a model of discrete losses based on the beamsplitter approach and a generalized continuous loss model based on the spatial Langevin equation. For an important class of Gaussian states, we derive master equations
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Tight bounds for antidistinguishability and circulant sets of pure quantum states Quantum (IF 5.1) Pub Date : 2025-02-04 Nathaniel Johnston, Vincent Russo, Jamie Sikora
A set of pure quantum states is said to be antidistinguishable if upon sampling one at random, there exists a measurement to perfectly determine some state that was not sampled. We show that antidistinguishability of a set of $n$ pure states is equivalent to a property of its Gram matrix called $(n-1)$-incoherence, thus establishing a connection with quantum resource theories that lets us apply a wide
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Characterization and thermometry of dissipatively stabilized steady states Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-04 G S Grattan, A M Liguori-Schremp, D Rodriguez Perez, E Kapit, W Jones and P Graf
In this work we study the properties of dissipatively stabilized steady states of noisy quantum algorithms, exploring the extent to which they can be well approximated as thermal distributions, and proposing methods to extract the effective temperature T. We study an algorithm called the relaxational quantum eigensolver (RQE), which is one of a family of algorithms that attempt to find ground states
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Heat transport in the quantum Rabi model: universality and ultrastrong coupling effects Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-04 L Magazzù, E Paladino and M Grifoni
Heat transport in a qubit–oscillator junction described by the quantum Rabi model is investigated. Upon variation of temperature, bias on the qubit and the qubit–oscillator coupling strength, a rich variety of effects is identified. For weak coupling to bosonic heat baths, transport is essentially controlled by the qubit–oscillator coupling g which defines a Kondo-like temperature . At temperatures
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State estimation with quantum extreme learning machines beyond the scrambling time npj Quantum Inform. (IF 6.6) Pub Date : 2025-02-03 Marco Vetrano, Gabriele Lo Monaco, Luca Innocenti, Salvatore Lorenzo, G. Massimo Palma
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Programmable quantum circuits in a large-scale photonic waveguide array npj Quantum Inform. (IF 6.6) Pub Date : 2025-02-03 Yang Yang, Robert J. Chapman, Akram Youssry, Ben Haylock, Francesco Lenzini, Mirko Lobino, Alberto Peruzzo
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Security of hybrid BB84 with heterodyne detection Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-03 Jasminder S Sidhu, Rocco Maggi, Saverio Pascazio and Cosmo Lupo
Quantum key distribution (QKD) promises everlasting security based on the laws of physics. Most common protocols are grouped into two distinct categories based on the degrees of freedom used to carry information, which can be either discrete or continuous, each presenting unique advantages in either performance, feasibility for near-term implementation, and compatibility with existing telecommunications
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Robustness of diabatic enhancement in quantum annealing Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-02-03 Natasha Feinstein, Ivan Shalashilin, Sougato Bose and P A Warburton
In adiabatic quantum annealing, the speed with which an anneal can be run, while still achieving a high final ground state (GS) fidelity, is dictated by the size of the minimum gap that appears between the ground and first excited state in the annealing spectrum. To avoid the exponential slowdown associated with exponentially closing gaps, diabatic transitions to higher energy levels may be exploited
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Scalable high-dimensional multipartite entanglement with trapped ions Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-31 Harsh Vardhan Upadhyay, Sanket Tripathy, Ting Rei Tan, Baladitya Suri and Athreya Shankar
We propose a protocol for the preparation of generalized Greenberger–Horne–Zeilinger (GHZ) states of N atoms each with d = 3 or 4 internal levels. We generalize the celebrated one-axis twisting (OAT) Hamiltonian for N qubits to qudits by including OAT interactions of equal strengths between every pair of qudit levels, a protocol we call as balanced OAT (BOAT). Analogous to OAT for qubits, we find that
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Towards enhanced precision in thermometry with nonlinear qubits Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-29 Sebastian Deffner
Quantum thermometry refers to the study of measuring ultra-low temperatures in quantum systems. The precision of such a quantum thermometer is limited by the degree to which temperature can be estimated by quantum measurements. More precisely, the maximal precision is given by the inverse of the quantum Fisher information. In the present analysis, we show that quantum thermometers that are described
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Using magnetic dynamics to measure the spin gap in a candidate Kitaev material npj Quant. Mater. (IF 5.4) Pub Date : 2025-02-01 Xinyi Jiang, Qingzheng Qiu, Cheng Peng, Hoyoung Jang, Wenjie Chen, Xianghong Jin, Li Yue, Byungjune Lee, Sang-Youn Park, Minseok Kim, Hyeong-Do Kim, Xinqiang Cai, Qizhi Li, Tao Dong, Nanlin Wang, Joshua J. Turner, Yuan Li, Yao Wang, Yingying Peng
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Beyond unital noise in variational quantum algorithms: noise-induced barren plateaus and limit sets Quantum (IF 5.1) Pub Date : 2025-01-30 Phattharaporn Singkanipa, Daniel A. Lidar
Variational quantum algorithms (VQAs) hold much promise but face the challenge of exponentially small gradients. Unmitigated, this barren plateau (BP) phenomenon leads to an exponential training overhead for VQAs. Perhaps the most pernicious are noise-induced barren plateaus (NIBPs), a type of unavoidable BP arising from open system effects, which have so far been shown to exist for unital noise maps
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Distance-preserving stabilizer measurements in hypergraph product codes Quantum (IF 5.1) Pub Date : 2025-01-30 Argyris Giannisis Manes, Jahan Claes
Unlike the surface code, quantum low-density parity-check (QLDPC) codes can have a finite encoding rate, potentially lowering the error correction overhead. However, finite-rate QLDPC codes have nonlocal stabilizers, making it difficult to design stabilizer measurement circuits that are low-depth and do not decrease the effective distance. Here, we demonstrate that a popular family of finite-rate QLDPC
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Z2 flux binding to higher-spin impurities in the Kitaev spin liquid npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-29 Masahiro O. Takahashi, Wen-Han Kao, Satoshi Fujimoto, Natalia B. Perkins
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Fundamental charges for dual-unitary circuits Quantum (IF 5.1) Pub Date : 2025-01-30 Tom Holden-Dye, Lluis Masanes, Arijeet Pal
Dual-unitary quantum circuits have recently attracted attention as an analytically tractable model of many-body quantum dynamics. Consisting of a 1+1D lattice of 2-qudit gates arranged in a 'brickwork' pattern, these models are defined by the constraint that each gate must remain unitary under swapping the roles of space and time. This dual-unitarity restricts the dynamics of local operators in these
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Measurement events relative to temporal quantum reference frames Quantum (IF 5.1) Pub Date : 2025-01-30 Ladina Hausmann, Alexander Schmidhuber, Esteban Castro-Ruiz
The Page-Wootters formalism is a proposal for reconciling the background-dependent, quantum-mechanical notion of time with the background independence of general relativity. However, the physical meaning of this framework remains debated. In this work, we compare two consistent approaches to the Page-Wootters formalism to clarify the operational meaning of evolution and measurements with respect to
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Intrinsic constraint on Tc for unconventional superconductivity npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-29 Qiong Qin, Yi-feng Yang
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High-dimensional coherent one-way quantum key distribution npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-29 Kfir Sulimany, Guy Pelc, Rom Dudkiewicz, Simcha Korenblit, Hagai S. Eisenberg, Yaron Bromberg, Michael Ben-Or
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Tantalum airbridges for scalable superconducting quantum processors npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-29 Kunliang Bu, Sainan Huai, Zhenxing Zhang, Dengfeng Li, Yuan Li, Jingjing Hu, Xiaopei Yang, Maochun Dai, Tianqi Cai, Yi-Cong Zheng, Shengyu Zhang
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Gate modulation of the hole singlet-triplet qubit frequency in germanium npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-29 John Rooney, Zhentao Luo, Lucas E. A. Stehouwer, Giordano Scappucci, Menno Veldhorst, Hong-Wen Jiang
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Discovery of new topological insulators and semimetals using deep generative models npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-28 Tao Hong, Taikang Chen, Dalong Jin, Yu Zhu, Heng Gao, Kun Zhao, Tongyi Zhang, Wei Ren, Guixin Cao
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Mitigating errors in analog quantum simulation by Hamiltonian reshaping or Hamiltonian rescaling npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-28 Rui-Cheng Guo, Yanwu Gu, Dong E. Liu
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Codes for entanglement-assisted classical communication npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-27 Tushita Prasad, Markus Grassl
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Designing open quantum systems with known steady states: Davies generators and beyond Quantum (IF 5.1) Pub Date : 2025-01-28 Jinkang Guo, Oliver Hart, Chi-Fang Chen, Aaron J. Friedman, Andrew Lucas
We provide a systematic framework for constructing generic models of nonequilibrium quantum dynamics with a target stationary (mixed) state. Our framework identifies (almost) all combinations of Hamiltonian and dissipative dynamics that relax to a steady state of interest, generalizing the Davies’ generator for dissipative relaxation at finite temperature to nonequilibrium dynamics targeting arbitrary
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Multiplexed Quantum Communication with Surface and Hypergraph Product Codes Quantum (IF 5.1) Pub Date : 2025-01-28 Shin Nishio, Nicholas Connolly, Nicolò Lo Piparo, William John Munro, Thomas Rowan Scruby, Kae Nemoto
Connecting multiple processors via quantum interconnect technologies could help overcome scalability issues in single-processor quantum computers. Transmission via these interconnects can be performed more efficiently using quantum multiplexing, where information is encoded in high-dimensional photonic degrees of freedom. We explore the effects of multiplexing on logical error rates in surface codes
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A thermodynamically consistent approach to the energy costs of quantum measurements Quantum (IF 5.1) Pub Date : 2025-01-28 Camille L Latune, Cyril Elouard
Considering a general microscopic model for a quantum measuring apparatus comprising a quantum probe coupled to a thermal bath, we analyze the energetic resources necessary for the realization of a quantum measurement, which includes the creation of system-apparatus correlations, the irreversible transition to a statistical mixture of definite outcomes, and the apparatus resetting. Crucially, we do
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Quantum algorithm for polaritonic chemistry based on an exact ansatz Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-28 Samuel Warren, Yuchen Wang, Carlos L Benavides-Riveros and David A Mazziotti
Cavity-modified chemistry uses strong light-matter interactions to modify the electronic properties of molecules in order to enable new physical phenomena such as novel reaction pathways. As cavity chemistry often involves critical regions where configurations become nearly degenerate, the ability to treat multireference problems is crucial to understanding polaritonic systems. In this Letter, we show
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Quantum data encoding as a distinct abstraction layer in the design of quantum circuits Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-28 Gabriele Agliardi and Enrico Prati
Complex quantum circuits are constituted by combinations of quantum subroutines. The computation is possible as long as the quantum data encoding is consistent throughout the circuit. Despite its fundamental importance, the formalization of quantum data encoding has never been addressed systematically so far. We formalize the concept of quantum data encoding, namely the format providing a representation
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2.5-dimensional topological superconductivity in twisted superconducting flakes npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-27 Kevin P. Lucht, J. H. Pixley, Pavel A. Volkov
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Quantum order by disorder is a key to understanding the magnetic phases of BaCo2(AsO4)2 npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-27 Sangyun Lee, Shengzhi Zhang, S. M. Thomas, L. Pressley, C. A. Bridges, Eun Sang Choi, Vivien S. Zapf, Stephen M. Winter, Minseong Lee
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On the simulation of quantum multimeters Quantum (IF 5.1) Pub Date : 2025-01-27 Andreas Bluhm, Leevi Leppäjärvi, Ion Nechita
In the quest for robust and universal quantum devices, the notion of simulation plays a crucial role, both from a theoretical and from an applied perspective. In this work, we go beyond the simulation of quantum channels and quantum measurements, studying what it means to simulate a collection of measurements, which we call a multimeter. To this end, we first explicitly characterize the completely
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Color code decoder with improved scaling for correcting circuit-level noise Quantum (IF 5.1) Pub Date : 2025-01-27 Seok-Hyung Lee, Andrew Li, Stephen D. Bartlett
Two-dimensional color codes are a promising candidate for fault-tolerant quantum computing, as they have high encoding rates, transversal implementation of logical Clifford gates, and resource-efficient magic state preparation schemes. However, decoding color codes presents a significant challenge due to their structure, where elementary errors violate three checks instead of just two (a key feature
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Relational dynamics and Page-Wootters formalism in group field theory Quantum (IF 5.1) Pub Date : 2025-01-27 Andrea Calcinari, Steffen Gielen
Group field theory posits that spacetime is emergent and is hence defined without any background notion of space or time; dynamical questions are formulated in relational terms, in particular using (scalar) matter degrees of freedom as time. Unlike in canonical quantisation of gravitational systems, there is no obvious notion of coordinate transformations or constraints, and established quantisation
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Security of differential phase shift QKD from relativistic principles Quantum (IF 5.1) Pub Date : 2025-01-27 Martin Sandfuchs, Marcus Haberland, V. Vilasini, Ramona Wolf
The design of quantum protocols for secure key generation poses many challenges: On the one hand, they need to be practical concerning experimental realisations. On the other hand, their theoretical description must be simple enough to allow for a security proof against all possible attacks. Often, these two requirements are in conflict with each other, and the differential phase shift (DPS) QKD protocol
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Distributing quantum correlations through local operations and classical resources Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-27 Adam G Hawkins, Hannah McAleese and Mauro Paternostro
Distributing quantum correlations to each node of a network is a key aspect of quantum networking. Here, we present a robust, physically motivated protocol by which global quantum correlations, as characterized by the discord, can be distributed to quantum memories using a mixed state of information carriers which possesses only classical correlations. In addition, such distribution is done using only
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Symmetry protected topological phases under decoherence Quantum (IF 5.1) Pub Date : 2025-01-23 Jong Yeon Lee, Yi-Zhuang You, Cenke Xu
We investigate mixed states exhibiting nontrivial topological features, focusing on symmetry-protected topological (SPT) phases under various types of decoherence. Our findings demonstrate that these systems can retain topological information from the SPT ground state despite decoherence. In the ''doubled Hilbert space,'' we define symmetry-protected topological ensembles (SPT ensembles) and examine
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Faster-than-Clifford simulations of entanglement purification circuits and their full-stack optimization npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-23 Vaishnavi L. Addala, Shu Ge, Stefan Krastanov
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Fabrication and characterization of low-loss Al/Si/Al parallel plate capacitors for superconducting quantum information applications npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-22 Anthony P. McFadden, Aranya Goswami, Tongyu Zhao, Teun van Schijndel, Trevyn F. Q. Larson, Sudhir Sahu, Stephen Gill, Florent Lecocq, Raymond Simmonds, Chris Palmstrøm
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Optimizing Circuit Reusing and its Application in Randomized Benchmarking Quantum (IF 5.1) Pub Date : 2025-01-23 Zhuo Chen, Guoding Liu, Xiongfeng Ma
Quantum learning tasks often leverage randomly sampled quantum circuits to characterize unknown systems. An efficient approach known as ``circuit reusing,'' where each circuit is executed multiple times, reduces the cost compared to implementing new circuits. This work investigates the optimal reusing times that minimizes the variance of measurement outcomes for a given experimental cost. We establish
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Pressure-dependent magnetism of the Kitaev candidate Li2RhO3 npj Quant. Mater. (IF 5.4) Pub Date : 2025-01-22 Bin Shen, Efrain Insuasti Pazmino, Ramesh Dhakal, Friedrich Freund, Philipp Gegenwart, Stephen M. Winter, Alexander A. Tsirlin
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Atom interferometer as a freely falling clock for time-dilation measurements Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-22 Albert Roura
Light-pulse atom interferometers based on single-photon transitions are a promising tool for gravitational-wave detection in the mid-frequency band and the search for ultralight dark-matter fields. Here we present a novel measurement scheme that enables their use as freely falling clocks directly measuring relativistic time-dilation effects. The proposal is particularly timely because it can be implemented
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Streaming quantum state purification Quantum (IF 5.1) Pub Date : 2025-01-21 Andrew M. Childs, Honghao Fu, Debbie Leung, Zhi Li, Maris Ozols, Vedang Vyas
Quantum state purification is the task of recovering a nearly pure copy of an unknown pure quantum state using multiple noisy copies of the state. This basic task has applications to quantum communication over noisy channels and quantum computation with imperfect devices, but has only been studied previously for the case of qubits. We derive an efficient purification procedure based on the swap test
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Linear gate bounds against natural functions for position-verification Quantum (IF 5.1) Pub Date : 2025-01-21 Vahid Asadi, Richard Cleve, Eric Culf, Alex May
A quantum position-verification scheme attempts to verify the spatial location of a prover. The prover is issued a challenge with quantum and classical inputs and must respond with appropriate timings. We consider two well-studied position-verification schemes known as $f$-routing and $f$-BB84. Both schemes require an honest prover to locally compute a classical function $f$ of inputs of length $n$
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Imperfect quantum networks with tailored resource states Quantum (IF 5.1) Pub Date : 2025-01-21 Maria Flors Mor-Ruiz, Julius Wallnöfer, Wolfgang Dür
Entanglement-based quantum networks exhibit a unique flexibility in the choice of entangled resource states that are then locally manipulated by the nodes to fulfill any request in the network. Furthermore, this manipulation is not uniquely defined and thus can be optimized. We tailor the adaptation of the resource state or pre-established entanglement to achieve bipartite communication in an imperfect
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Long-time error-mitigating simulation of open quantum systems on near term quantum computers npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-21 Brian Rost, Lorenzo Del Re, Nathan Earnest, Alexander F. Kemper, Barbara Jones, James K. Freericks
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Breaking barriers in two-party quantum cryptography via stochastic semidefinite programming Quantum (IF 5.1) Pub Date : 2025-01-20 Akshay Bansal, Jamie Sikora
In the last two decades, there has been much effort in finding secure protocols for two-party cryptographic tasks. It has since been discovered that even with quantum mechanics, many such protocols are limited in their security promises. In this work, we use stochastic selection, an idea from stochastic programming, to circumvent such limitations. For example, we find a way to switch between bit commitment
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Learning to classify quantum phases of matter with a few measurements Quantum Sci. Technol. (IF 5.6) Pub Date : 2025-01-20 Mehran Khosrojerdi, Jason L Pereira, Alessandro Cuccoli and Leonardo Banchi
We study the identification of quantum phases of matter, at zero temperature, when only part of the phase diagram is known in advance. Following a supervised learning approach, we show how to use our previous knowledge to construct an observable capable of classifying the phase even in the unknown region. By using a combination of classical and quantum techniques, such as tensor networks, kernel methods
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Bipartite polygon models: entanglement classes and their nonlocal behaviour Quantum (IF 5.1) Pub Date : 2025-01-20 Mayalakshmi Kolangatt, Thigazholi Muruganandan, Sahil Gopalkrishna Naik, Tamal Guha, Manik Banik, Sutapa Saha
Hardy's argument constitutes an elegantly logical test for identifying nonlocal features of multipartite correlations. In this paper, we investigate Hardy's nonlocal behavior within a broad class of operational theories, including the qubit state space as a specific case. Specifically, we begin by examining a wider range of operational models with state space descriptions in the form of regular polygons
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Sparse Blossom: correcting a million errors per core second with minimum-weight matching Quantum (IF 5.1) Pub Date : 2025-01-20 Oscar Higgott, Craig Gidney
In this work, we introduce a fast implementation of the minimum-weight perfect matching (MWPM) decoder, the most widely used decoder for several important families of quantum error correcting codes, including surface codes. Our algorithm, which we call sparse blossom, is a variant of the blossom algorithm which directly solves the decoding problem relevant to quantum error correction. Sparse blossom
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Hexagons govern three-qubit contextuality Quantum (IF 5.1) Pub Date : 2025-01-20 Metod Saniga, Frédéric Holweck, Colm Kelleher, Axel Muller, Alain Giorgetti, Henri de Boutray
Split Cayley hexagons of order two are distinguished finite geometries living in the three-qubit symplectic polar space in two different forms, called classical and skew. Although neither of the two yields observable-based contextual configurations of their own, $classically$-embedded copies are found to fully encode contextuality properties of the most prominent three-qubit contextual configurations
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Dephasing enabled fast charging of quantum batteries npj Quantum Inform. (IF 6.6) Pub Date : 2025-01-19 Rahul Shastri, Chao Jiang, Guo-Hua Xu, B. Prasanna Venkatesh, Gentaro Watanabe