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Unconventional superconductivity near a nematic instability in a multi-orbital system npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-15 Kazi Ranjibul Islam, Andrey Chubukov
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Test for BCS-BEC crossover in the cuprate superconductors npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-15 Qijin Chen, Zhiqiang Wang, Rufus Boyack, K. Levin
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Flat-band hybridization between f and d states near the Fermi energy of SmCoIn5 npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-14 David W. Tam, Nicola Colonna, Fatima Alarab, Vladimir N. Strocov, Dariusz Jakub Gawryluk, Ekaterina Pomjakushina, Michel Kenzelmann
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Transformations in quantum networks via local operations assisted by finitely many rounds of classical communication Quantum (IF 6.4) Pub Date : 2024-03-14 Cornelia Spee, Tristan Kraft
Recent advances have led towards first prototypes of quantum networks in which entanglement is distributed by sources producing bipartite entangled states. This raises the question of which states can be generated in quantum networks based on bipartite sources using local operations and classical communication. In this work, we study state transformations under finite rounds of local operations and
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Can Error Mitigation Improve Trainability of Noisy Variational Quantum Algorithms? Quantum (IF 6.4) Pub Date : 2024-03-14 Samson Wang, Piotr Czarnik, Andrew Arrasmith, M. Cerezo, Lukasz Cincio, Patrick J. Coles
Variational Quantum Algorithms (VQAs) are often viewed as the best hope for near-term quantum advantage. However, recent studies have shown that noise can severely limit the trainability of VQAs, e.g., by exponentially flattening the cost landscape and suppressing the magnitudes of cost gradients. Error Mitigation (EM) shows promise in reducing the impact of noise on near-term devices. Thus, it is
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Low disorder and high valley splitting in silicon npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-13 Davide Degli Esposti, Lucas E. A. Stehouwer, Önder Gül, Nodar Samkharadze, Corentin Déprez, Marcel Meyer, Ilja N. Meijer, Larysa Tryputen, Saurabh Karwal, Marc Botifoll, Jordi Arbiol, Sergey V. Amitonov, Lieven M. K. Vandersypen, Amir Sammak, Menno Veldhorst, Giordano Scappucci
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Short-depth QAOA circuits and quantum annealing on higher-order ising models npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-12 Elijah Pelofske, Andreas Bärtschi, Stephan Eidenbenz
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Pipeline quantum processor architecture for silicon spin qubits npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-12 S. M. Patomäki, M. F. Gonzalez-Zalba, M. A. Fogarty, Z. Cai, S. C. Benjamin, J. J. L. Morton
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Teleportation of Post-Selected Quantum States Quantum (IF 6.4) Pub Date : 2024-03-14 Daniel Collins
Teleportation allows Alice to send a pre-prepared quantum state to Bob using only pre-shared entanglement and classical communication. Here we show that it is possible to teleport a state which is also $\it{post}$-selected. Post-selection of a state $\Phi$ means that after Alice has finished her experiment she performs a measurement and only keeps runs of the experiment where the measurement outcome
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Compiling Quantum Circuits for Dynamically Field-Programmable Neutral Atoms Array Processors Quantum (IF 6.4) Pub Date : 2024-03-14 Daniel Bochen Tan, Dolev Bluvstein, Mikhail D. Lukin, Jason Cong
Dynamically field-programmable qubit arrays (DPQA) have recently emerged as a promising platform for quantum information processing. In DPQA, atomic qubits are selectively loaded into arrays of optical traps that can be reconfigured during the computation itself. Leveraging qubit transport and parallel, entangling quantum operations, different pairs of qubits, even those initially far away, can be
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Entanglement Trajectory and its Boundary Quantum (IF 6.4) Pub Date : 2024-03-14 Ruge Lin
In this article, we present a novel approach to investigating entanglement in the context of quantum computing. Our methodology involves analyzing reduced density matrices at different stages of a quantum algorithm's execution and representing the dominant eigenvalue and von Neumann entropy on a graph, creating an "entanglement trajectory." To establish the trajectory's boundaries, we employ random
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A structure theorem for generalized-noncontextual ontological models Quantum (IF 6.4) Pub Date : 2024-03-14 David Schmid, John H. Selby, Matthew F. Pusey, Robert W. Spekkens
It is useful to have a criterion for when the predictions of an operational theory should be considered classically explainable. Here we take the criterion to be that the theory admits of a generalized-noncontextual ontological model. Existing works on generalized noncontextuality have focused on experimental scenarios having a simple structure: typically, prepare-measure scenarios. Here, we formally
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Basic quantum subroutines: finding multiple marked elements and summing numbers Quantum (IF 6.4) Pub Date : 2024-03-14 Joran van Apeldoorn, Sander Gribling, Harold Nieuwboer
We show how to find all $k$ marked elements in a list of size $N$ using the optimal number $O(\sqrt{N k})$ of quantum queries and only a polylogarithmic overhead in the gate complexity, in the setting where one has a small quantum memory. Previous algorithms either incurred a factor $k$ overhead in the gate complexity, or had an extra factor $\log(k)$ in the query complexity. We then consider the problem
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Stabilization of Hubbard-Thouless pumps through nonlocal fermionic repulsion Quantum (IF 6.4) Pub Date : 2024-03-14 Javier Argüello-Luengo, Manfred J. Mark, Francesca Ferlaino, Maciej Lewenstein, Luca Barbiero, Sergi Julià-Farré
Thouless pumping represents a powerful concept to probe quantized topological invariants in quantum systems. We explore this mechanism in a generalized Rice-Mele Fermi-Hubbard model characterized by the presence of competing onsite and intersite interactions. Contrary to recent experimental and theoretical results, showing a breakdown of quantized pumping induced by the onsite repulsion, we prove that
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Quantum circuits for toric code and X-cube fracton model Quantum (IF 6.4) Pub Date : 2024-03-13 Penghua Chen, Bowen Yan, Shawn X. Cui
We propose a systematic and efficient quantum circuit composed solely of Clifford gates for simulating the ground state of the surface code model. This approach yields the ground state of the toric code in $\lceil 2L+2+log_{2}(d)+\frac{L}{2d} \rceil$ time steps, where $L$ refers to the system size and $d$ represents the maximum distance to constrain the application of the CNOT gates. Our algorithm
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Variational Phase Estimation with Variational Fast Forwarding Quantum (IF 6.4) Pub Date : 2024-03-13 Maria-Andreea Filip, David Muñoz Ramo, Nathan Fitzpatrick
Subspace diagonalisation methods have appeared recently as promising means to access the ground state and some excited states of molecular Hamiltonians by classically diagonalising small matrices, whose elements can be efficiently obtained by a quantum computer. The recently proposed Variational Quantum Phase Estimation (VQPE) algorithm uses a basis of real time-evolved states, for which the energy
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Time-optimal multi-qubit gates: Complexity, efficient heuristic and gate-time bounds Quantum (IF 6.4) Pub Date : 2024-03-13 Pascal Baßler, Markus Heinrich, Martin Kliesch
Multi-qubit entangling interactions arise naturally in several quantum computing platforms and promise advantages over traditional two-qubit gates. In particular, a fixed multi-qubit Ising-type interaction together with single-qubit X-gates can be used to synthesize global ZZ-gates (GZZ gates). In this work, we first show that the synthesis of such quantum gates that are time-optimal is NP-hard. Second
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Simulating photosynthetic energy transport on a photonic network npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-11 Hao Tang, Xiao-Wen Shang, Zi-Yu Shi, Tian-Shen He, Zhen Feng, Tian-Yu Wang, Ruoxi Shi, Hui-Ming Wang, Xi Tan, Xiao-Yun Xu, Yao Wang, Jun Gao, M. S. Kim, Xian-Min Jin
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Two-dimensional phase diagram of the charge density wave in doped CsV3Sb5 npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-09 Linwei Huai, Hongyu Li, Yulei Han, Yang Luo, Shuting Peng, Zhiyuan Wei, Jianchang Shen, Bingqian Wang, Yu Miao, Xiupeng Sun, Zhipeng Ou, Bo Liu, Xiaoxiao Yu, Ziji Xiang, Min-Quan Kuang, Zhenhua Qiao, Xianhui Chen, Junfeng He
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One-dimensional topological phase and tunable soliton states in atomic nanolines on Si(001) surface npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-09 Biyu Song, Guoxiang Zhi, Chenqiang Hua, Meimei Wu, Wenzhen Dou, Wenjin Gao, Tianzhao Li, Tianchao Niu, Miao Zhou
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Field-controlled multicritical behavior and emergent universality in fully frustrated quantum magnets npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-09 Yuchen Fan, Ning Xi, Changle Liu, Bruce Normand, Rong Yu
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Here comes the SU(N): multivariate quantum gates and gradients Quantum (IF 6.4) Pub Date : 2024-03-07 Roeland Wiersema, Dylan Lewis, David Wierichs, Juan Carrasquilla, Nathan Killoran
Variational quantum algorithms use non-convex optimization methods to find the optimal parameters for a parametrized quantum circuit in order to solve a computational problem. The choice of the circuit ansatz, which consists of parameterized gates, is crucial to the success of these algorithms. Here, we propose a gate which fully parameterizes the special unitary group $\mathrm{SU}(N)$. This gate is
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Unconventional superconductivity in Cr-based compound Pr3Cr10−xN11 npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-06 C. S. Chen, Q. Wu, M. Y. Zou, Z. H. Zhu, Y. X. Yang, C. Tan, A. D. Hillier, J. Chang, J. L. Luo, W. Wu, L. Shu
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Hybrid-order topological superconductivity in a topological metal 1T’-MoTe2 npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-05 Sheng-Jie Huang, Kyungwha Park, Yi-Ting Hsu
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Non-symmetric Pauli spin blockade in a silicon double quantum dot npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-06 Theodor Lundberg, David J. Ibberson, Jing Li, Louis Hutin, José C. Abadillo-Uriel, Michele Filippone, Benoit Bertrand, Andreas Nunnenkamp, Chang-Min Lee, Nadia Stelmashenko, Jason W. A. Robinson, Maud Vinet, Lisa Ibberson, Yann-Michel Niquet, M. Fernando Gonzalez-Zalba
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Analyzing variational quantum landscapes with information content npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-29 Adrián Pérez-Salinas, Hao Wang, Xavier Bonet-Monroig
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Ergodicity Breaking Under Confinement in Cold-Atom Quantum Simulators Quantum (IF 6.4) Pub Date : 2024-02-29 Jean-Yves Desaules, Guo-Xian Su, Ian P. McCulloch, Bing Yang, Zlatko Papić, Jad C. Halimeh
The quantum simulation of gauge theories on synthetic quantum matter devices has gained a lot of traction in the last decade, making possible the observation of a range of exotic quantum many-body phenomena. In this work, we consider the spin-$1/2$ quantum link formulation of $1+1$D quantum electrodynamics with a topological $\theta$-angle, which can be used to tune a confinement-deconfinement transition
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Variational quantum algorithm for experimental photonic multiparameter estimation npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-28 Valeria Cimini, Mauro Valeri, Simone Piacentini, Francesco Ceccarelli, Giacomo Corrielli, Roberto Osellame, Nicolò Spagnolo, Fabio Sciarrino
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Bicolor loop models and their long range entanglement Quantum (IF 6.4) Pub Date : 2024-02-29 Zhao Zhang
Quantum loop models are well studied objects in the context of lattice gauge theories and topological quantum computing. They usually carry long range entanglement that is captured by the topological entanglement entropy. I consider generalization of the toric code model to bicolor loop models and show that the long range entanglement can be reflected in three different ways: a topologically invariant
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Identifying families of multipartite states with non-trivial local entanglement transformations Quantum (IF 6.4) Pub Date : 2024-02-29 Nicky Kai Hong Li, Cornelia Spee, Martin Hebenstreit, Julio I. de Vicente, Barbara Kraus
The study of state transformations by spatially separated parties with local operations assisted by classical communication (LOCC) plays a crucial role in entanglement theory and its applications in quantum information processing. Transformations of this type among pure bipartite states were characterized long ago and have a revealing theoretical structure. However, it turns out that generic fully
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Dynamical quantum phase transitions from random matrix theory Quantum (IF 6.4) Pub Date : 2024-02-29 David Pérez-García, Leonardo Santilli, Miguel Tierz
We uncover a novel dynamical quantum phase transition, using random matrix theory and its associated notion of planar limit. We study it for the isotropic XY Heisenberg spin chain. For this, we probe its real-time dynamics through the Loschmidt echo. This leads to the study of a random matrix ensemble with a complex weight, whose analysis requires novel technical considerations, that we develop. We
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Entanglement-symmetries of covariant channels Quantum (IF 6.4) Pub Date : 2024-02-29 Dominic Verdon
Let $G$ and $G'$ be monoidally equivalent compact quantum groups, and let $H$ be a Hopf-Galois object realising a monoidal equivalence between these groups' representation categories. This monoidal equivalence induces an equivalence Chan($G$) $\rightarrow$ Chan($G'$), where Chan($G$) is the category whose objects are finite-dimensional $C*$-algebras with an action of G and whose morphisms are covariant
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Entanglement dynamics of photon pairs and quantum memories in the gravitational field of the earth Quantum (IF 6.4) Pub Date : 2024-02-29 Roy Barzel, Mustafa Gündoğan, Markus Krutzik, Dennis Rätzel, Claus Lämmerzahl
We investigate the effect of entanglement dynamics due to gravity – the basis of a mechanism of universal decoherence – for photonic states and quantum memories in Mach-Zehnder and Hong-Ou-Mandel interferometry setups in the gravitational field of the earth. We show that chances are good to witness the effect with near-future technology in Hong-Ou-Mandel interferometry. This would represent an experimental
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Towards a measurement theory in QFT: “Impossible” quantum measurements are possible but not ideal Quantum (IF 6.4) Pub Date : 2024-02-27 Nicolas Gisin, Flavio Del Santo
Naive attempts to put together relativity and quantum measurements lead to signaling between space-like separated regions. In QFT, these are known as $\textit{impossible measurements}$. We show that the same problem arises in non-relativistic quantum physics, where joint nonlocal measurements (i.e., between systems kept spatially separated) in general lead to signaling, while one would expect no-signaling
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Miniaturized optics from structured nanoscale cavities Prog. Quant. Electron. (IF 11.7) Pub Date : 2024-02-27 Danqing Wang, Ankun Yang
Miniaturized and rationally assembled nanostructures exhibit extraordinarily distinct physical properties beyond their individual units. This review will focus on structured small-scale optical cavities, especially on plasmonic nanoparticle lattices that show unique electromagnetic near fields from collective optical coupling. By harnessing different material systems and structural designs, various
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Improved Accuracy for Trotter Simulations Using Chebyshev Interpolation Quantum (IF 6.4) Pub Date : 2024-02-26 Gumaro Rendon, Jacob Watkins, Nathan Wiebe
Quantum metrology allows for measuring properties of a quantum system at the optimal Heisenberg limit. However, when the relevant quantum states are prepared using digital Hamiltonian simulation, the accrued algorithmic errors will cause deviations from this fundamental limit. In this work, we show how algorithmic errors due to Trotterized time evolution can be mitigated through the use of standard
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Towards experimental classical verification of quantum computation Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-26 Roman Stricker, Jose Carrasco, Martin Ringbauer, Lukas Postler, Michael Meth, Claire Edmunds, Philipp Schindler, Rainer Blatt, Peter Zoller, Barbara Kraus, Thomas Monz
With today’s quantum processors venturing into regimes beyond the capabilities of classical devices, we face the challenge to verify that these devices perform as intended, even when we cannot check their results on classical computers. In a recent breakthrough in computer science, a protocol was developed that allows the verification of the output of a computation performed by an untrusted quantum
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Efficient bosonic nonlinear phase gates npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-23 Kimin Park, Radim Filip
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Advances in the transport of laser radiation to the brain with optical clearing: From simulation to reality Prog. Quant. Electron. (IF 11.7) Pub Date : 2024-02-24 Alaa Sabeeh Shanshool, Saeed Ziaee, Mohammad Ali Ansari, Valery V. Tuchin
Advanced laser methods have recently been used in human and animal head tissues for functional and molecular imaging. Combining these approaches with various probes and nanostructures gives up a new path for theranostic applications in brain tissues. The diverse optical properties of head tissues such as the scalp, skull, cerebrospinal fluid, and brain tissues result in considerable photon scattering
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Variational quantum algorithms for simulation of Lindblad dynamics Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-23 Tasneem M Watad, Netanel H Lindner
We introduce variational hybrid classical-quantum algorithms to simulate the Lindblad master equation and its adjoint for time-evolving Markovian open quantum systems and quantum observables. Our methods are based on a direct representation of density matrices and quantum observables as quantum superstates. We design and optimize low-depth variational quantum circuits that efficiently capture the unitary
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Experimental implementation of quantum-walk-based portfolio optimization Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-23 Dengke Qu, Edric Matwiejew, Kunkun Wang, Jingbo Wang, Peng Xue
The application of quantum algorithms has attracted much attention as it holds the promise of solving practical problems that are intractable to classical algorithms. One such application is the recent development of a quantum-walk-based optimization algorithm approach to portfolio optimization under the modern portfolio theory framework. In this paper, we demonstrate an experimental realization of
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Distinct switching of chiral transport in the kagome metals KV3Sb5 and CsV3Sb5 npj Quant. Mater. (IF 5.7) Pub Date : 2024-02-22 Chunyu Guo, Maarten R. van Delft, Martin Gutierrez-Amigo, Dong Chen, Carsten Putzke, Glenn Wagner, Mark H. Fischer, Titus Neupert, Ion Errea, Maia G. Vergniory, Steffen Wiedmann, Claudia Felser, Philip J. W. Moll
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Better-than-classical Grover search via quantum error detection and suppression npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-20 Bibek Pokharel, Daniel A. Lidar
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Analogue Quantum Simulation with Fixed-Frequency Transmon Qubits Quantum (IF 6.4) Pub Date : 2024-02-22 Sean Greenaway, Adam Smith, Florian Mintert, Daniel Malz
We experimentally assess the suitability of transmon qubits with fixed frequencies and fixed interactions for the realization of analogue quantum simulations of spin systems. We test a set of necessary criteria for this goal on a commercial quantum processor using full quantum process tomography and more efficient Hamiltonian tomography. Significant single qubit errors at low amplitudes are identified
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Accelerating Quantum Algorithms with Precomputation Quantum (IF 6.4) Pub Date : 2024-02-22 William J. Huggins, Jarrod R. McClean
Real-world applications of computing can be extremely time-sensitive. It would be valuable if we could accelerate such tasks by performing some of the work ahead of time. Motivated by this, we propose a cost model for quantum algorithms that allows quantum precomputation; i.e., for a polynomial amount of ``free'' computation before the input to an algorithm is fully specified, and methods for taking
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Quantum Vision Transformers Quantum (IF 6.4) Pub Date : 2024-02-22 El Amine Cherrat, Iordanis Kerenidis, Natansh Mathur, Jonas Landman, Martin Strahm, Yun Yvonna Li
In this work, quantum transformers are designed and analysed in detail by extending the state-of-the-art classical transformer neural network architectures known to be very performant in natural language processing and image analysis. Building upon the previous work, which uses parametrised quantum circuits for data loading and orthogonal neural layers, we introduce three types of quantum transformers
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Wide-field Fourier magnetic imaging with electron spins in diamond npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-21 Zhongzhi Guo, You Huang, Mingcheng Cai, Chunxing Li, Mengze Shen, Mengqi Wang, Pei Yu, Ya Wang, Fazhan Shi, Pengfei Wang, Jiangfeng Du
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Stabilizer Formalism for Operator Algebra Quantum Error Correction Quantum (IF 6.4) Pub Date : 2024-02-21 Guillaume Dauphinais, David W. Kribs, Michael Vasmer
We introduce a stabilizer formalism for the general quantum error correction framework called operator algebra quantum error correction (OAQEC), which generalizes Gottesman's formulation for traditional quantum error correcting codes (QEC) and Poulin's for operator quantum error correction and subsystem codes (OQEC). The construction generates hybrid classical-quantum stabilizer codes and we formulate
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Taming the Rotating Wave Approximation Quantum (IF 6.4) Pub Date : 2024-02-21 Daniel Burgarth, Paolo Facchi, Robin Hillier, Marilena Ligabò
The interaction between light and matter is one of the oldest research areas of quantum mechanics, and a field that just keeps on delivering new insights and applications. With the arrival of cavity and circuit quantum electrodynamics we can now achieve strong light-matter couplings which form the basis of most implementations of quantum technology. But quantum information processing also has high
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Fast generation of spin squeezing via resonant spin-boson coupling Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-21 Diego Barberena, Sean R Muleady, John J Bollinger, Robert J Lewis-Swan, Ana Maria Rey
We propose protocols for the creation of useful entangled states in a system of spins collectively coupled to a bosonic mode, directly applicable to trapped-ion and cavity QED setups. The protocols use coherent manipulations of the resonant spin-boson interactions naturally arising in these systems to prepare spin squeezed states exponentially fast in time. The resonance condition harnesses the full
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Hybrid actor-critic algorithm for quantum reinforcement learning at CERN beam lines Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-21 Michael Schenk, Elías F Combarro, Michele Grossi, Verena Kain, Kevin Shing Bruce Li, Mircea-Marian Popa, Sofia Vallecorsa
Free energy-based reinforcement learning (FERL) with clamped quantum Boltzmann machines (QBM) was shown to significantly improve the learning efficiency compared to classical Q-learning with the restriction, however, to discrete state-action space environments. In this paper, the FERL approach is extended to multi-dimensional continuous state-action space environments to open the doors for a broader
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A hybrid quantum algorithm to detect conical intersections Quantum (IF 6.4) Pub Date : 2024-02-20 Emiel Koridon, Joana Fraxanet, Alexandre Dauphin, Lucas Visscher, Thomas E. O'Brien, Stefano Polla
Conical intersections are topologically protected crossings between the potential energy surfaces of a molecular Hamiltonian, known to play an important role in chemical processes such as photoisomerization and non-radiative relaxation. They are characterized by a non-zero Berry phase, which is a topological invariant defined on a closed path in atomic coordinate space, taking the value $\pi$ when
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Reqomp: Space-constrained Uncomputation for Quantum Circuits Quantum (IF 6.4) Pub Date : 2024-02-19 Anouk Paradis, Benjamin Bichsel, Martin Vechev
Quantum circuits must run on quantum computers with tight limits on qubit and gate counts. To generate circuits respecting both limits, a promising opportunity is exploiting $uncomputation$ to trade qubits for gates. We present Reqomp, a method to automatically synthesize correct and efficient uncomputation of ancillae while respecting hardware constraints. For a given circuit, Reqomp can offer a wide
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A thermodynamic approach to optimization in complex quantum systems Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-16 Alberto Imparato, Nicholas Chancellor, Gabriele De Chiara
We consider the problem of finding the energy minimum of a complex quantum Hamiltonian by employing a non-Markovian bath prepared in a low energy state. The energy minimization problem is thus turned into a thermodynamic cooling protocol in which we repeatedly put the system of interest in contact with a colder auxiliary system. By tuning the internal parameters of the bath, we show that the optimal
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Doping-dependent charge- and spin-density wave orderings in a monolayer of Pb adatoms on Si(111) npj Quant. Mater. (IF 5.7) Pub Date : 2024-02-15 M. Vandelli, A. Galler, A. Rubio, A. I. Lichtenstein, S. Biermann, E. A. Stepanov
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Photonic entanglement during a zero-g flight Quantum (IF 6.4) Pub Date : 2024-02-15 Julius Arthur Bittermann, Lukas Bulla, Sebastian Ecker, Sebastian Philipp Neumann, Matthias Fink, Martin Bohmann, Nicolai Friis, Marcus Huber, Rupert Ursin
Quantum technologies have matured to the point that we can test fundamental quantum phenomena under extreme conditions. Specifically, entanglement, a cornerstone of modern quantum information theory, can be robustly produced and verified in various adverse environments. We take these tests further and implement a high-quality Bell experiment during a parabolic flight, transitioning from microgravity
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Rapid single-shot parity spin readout in a silicon double quantum dot with fidelity exceeding 99% npj Quantum Inform. (IF 7.6) Pub Date : 2024-02-13 Kenta Takeda, Akito Noiri, Takashi Nakajima, Leon C. Camenzind, Takashi Kobayashi, Amir Sammak, Giordano Scappucci, Seigo Tarucha
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Quantitative relations between different measurement contexts Quantum (IF 6.4) Pub Date : 2024-02-14 Ming Ji, Holger F. Hofmann
In quantum theory, a measurement context is defined by an orthogonal basis in a Hilbert space, where each basis vector represents a specific measurement outcome. The precise quantitative relation between two different measurement contexts can thus be characterized by the inner products of nonorthogonal states in that Hilbert space. Here, we use measurement outcomes that are shared by different contexts
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Continuous-time quantum walks for MAX-CUT are hot Quantum (IF 6.4) Pub Date : 2024-02-13 Robert J. Banks, Ehsan Haque, Farah Nazef, Fatima Fethallah, Fatima Ruqaya, Hamza Ahsan, Het Vora, Hibah Tahir, Ibrahim Ahmad, Isaac Hewins, Ishaq Shah, Krish Baranwal, Mannan Arora, Mateen Asad, Mubasshirah Khan, Nabian Hasan, Nuh Azad, Salgai Fedaiee, Shakeel Majeed, Shayam Bhuyan, Tasfia Tarannum, Yahya Ali, Dan E. Browne, P. A. Warburton
By exploiting the link between time-independent Hamiltonians and thermalisation, heuristic predictions on the performance of continuous-time quantum walks for MAX-CUT are made. The resulting predictions depend on the number of triangles in the underlying MAX-CUT graph. We extend these results to the time-dependent setting with multi-stage quantum walks and Floquet systems. The approach followed here