-
Black-hole powered quantum coherent amplifier npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-28 Avijit Misra, Pritam Chattopadhyay, Anatoly Svidzinsky, Marlan O. Scully, Gershon Kurizki
-
Modeling Si/SiGe quantum dot variability induced by interface disorder reconstructed from multiperspective microscopy npj Quantum Inform. (IF 7.6) Pub Date : 2024-03-27 Luis Fabián Peña, Justine C. Koepke, Joseph Houston Dycus, Andrew Mounce, Andrew D. Baczewski, N. Tobias Jacobson, Ezra Bussmann
-
Enriched string-net models and their excitations Quantum (IF 6.4) Pub Date : 2024-03-28 David Green, Peter Huston, Kyle Kawagoe, David Penneys, Anup Poudel, Sean Sanford
Boundaries of Walker-Wang models have been used to construct commuting projector models which realize chiral unitary modular tensor categories (UMTCs) as boundary excitations. Given a UMTC $\mathcal{A}$ representing the Witt class of an anomaly, the article [10] gave a commuting projector model associated to an $\mathcal{A}$-enriched unitary fusion category $\mathcal{X}$ on a 2D boundary of the 3D
-
Loss-tolerant architecture for quantum computing with quantum emitters Quantum (IF 6.4) Pub Date : 2024-03-28 Matthias C. Löbl, Stefano Paesani, Anders S. Sørensen
We develop an architecture for measurement-based quantum computing using photonic quantum emitters. The architecture exploits spin-photon entanglement as resource states and standard Bell measurements of photons for fusing them into a large spin-qubit cluster state. The scheme is tailored to emitters with limited memory capabilities since it only uses an initial non-adaptive (ballistic) fusion process
-
Randomized measurement protocols for lattice gauge theories Quantum (IF 6.4) Pub Date : 2024-03-27 Jacob Bringewatt, Jonathan Kunjummen, Niklas Mueller
Randomized measurement protocols, including classical shadows, entanglement tomography, and randomized benchmarking are powerful techniques to estimate observables, perform state tomography, or extract the entanglement properties of quantum states. While unraveling the intricate structure of quantum states is generally difficult and resource-intensive, quantum systems in nature are often tightly constrained
-
Effective versus Floquet theory for the Kerr parametric oscillator Quantum (IF 6.4) Pub Date : 2024-03-25 Ignacio García-Mata, Rodrigo G. Cortiñas, Xu Xiao, Jorge Chávez-Carlos, Victor S. Batista, Lea F. Santos, Diego A. Wisniacki
Parametric gates and processes engineered from the perspective of the static effective Hamiltonian of a driven system are central to quantum technology. However, the perturbative expansions used to derive static effective models may not be able to efficiently capture all the relevant physics of the original system. In this work, we investigate the conditions for the validity of the usual low-order
-
Dissipative stability and dynamical phase transition in two driven interacting qubits Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-03-26 K V Shulga
We examine a two-qubit system influenced by a time-periodic external field while interacting with a Markovian bath. This scenario significantly impacts the temporal coherence characteristics of the system. By solving the evolution equation for the density matrix operator, we determine the characteristic equilibration time and analyze the concurrence parameter-a key metric for quantifying entanglement
-
Single-hole spectra of Kitaev spin liquids: from dynamical Nagaoka ferromagnetism to spin-hole fractionalization npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-21 Wilhelm Kadow, Hui-Ke Jin, Johannes Knolle, Michael Knap
-
Efficient quantum amplitude encoding of polynomial functions Quantum (IF 6.4) Pub Date : 2024-03-21 Javier Gonzalez-Conde, Thomas W. Watts, Pablo Rodriguez-Grasa, Mikel Sanz
Loading functions into quantum computers represents an essential step in several quantum algorithms, such as quantum partial differential equation solvers. Therefore, the inefficiency of this process leads to a major bottleneck for the application of these algorithms. Here, we present and compare two efficient methods for the amplitude encoding of real polynomial functions on $n$ qubits. This case
-
Bulk-boundary correspondence in topological systems with the momentum dependent energy shift Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-03-22 Huan-Yu Wang, Zhen-Biao Yang, 0000-0002-1179-2061Wu-Ming Liu2
Bulk-boundary correspondence (BBC) remains the central topic in modern condensed matter physics and has received a boost of interest with the recent discovery of non-Hermitian skin effects. However, there still exist profound features of BBC that are beyond the existing framework. Here, we report the unexpected behavior of BBC when the Hamiltonian contains terms of the form d0(k)I , which serves as
-
Near MDS and near quantum MDS codes via orthogonal arrays Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-03-22 Shanqi Pang, Chaomeng Zhang, Mengqian Chen, Miaomiao Zhang
Near maximum distance separable (NMDS) codes are closely related to interesting objects in finite geometry and have nice applications in combinatorics and cryptography. But there are many unsolved problems about construction of NMDS codes. In this paper, by using symmetrical orthogonal arrays (OAs), we construct a lot of NMDS, m-MDS and almost extremal NMDS codes. Quantum error-correcting codes (QECCs)
-
Generating scalable graph states in an atom-nanophotonic interface Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-03-22 C-H Chien, S Goswami, C-C Wu, W-S Hiew, Y-C Chen, H H Jen
Scalable graph states are essential for measurement-based quantum computation and many entanglement-assisted applications in quantum technologies. Generation of these multipartite entangled states requires a controllable and efficient quantum device with delicate design of generation protocol. Here we propose to prepare high-fidelity and scalable graph states in one and two dimensions, which can be
-
Coherent phonon and unconventional carriers in the magnetic kagome metal Fe3Sn2 npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-21 Marcos V. Gonçalves-Faria, Alexej Pashkin, Qi Wang, Hechang C. Lei, Stephan Winnerl, Alexander A. Tsirlin, Manfred Helm, Ece Uykur
-
Mott physics in the multiflavored age npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-20 Frédéric Mila
The multiflavor Mott insulators, whose local Hilbert space consists of multiple degrees of freedom, occur widely in both quantum materials and ultracold atom systems. This Comment recommends the review article by Chen and Wu that is, to the author’s knowledge, the first one to deal with all aspects and physical realizations of the multiflavor Mott insulators.
-
Sequential hypothesis testing for continuously-monitored quantum systems Quantum (IF 6.4) Pub Date : 2024-03-20 Giulio Gasbarri, Matias Bilkis, Elisabet Roda-Salichs, John Calsamiglia
We consider a quantum system that is being continuously monitored, giving rise to a measurement signal. From such a stream of data, information needs to be inferred about the underlying system's dynamics. Here we focus on hypothesis testing problems and put forward the usage of sequential strategies where the signal is analyzed in real time, allowing the experiment to be concluded as soon as the underlying
-
Entanglement catalysis for quantum states and noisy channels Quantum (IF 6.4) Pub Date : 2024-03-20 Chandan Datta, Tulja Varun Kondra, Marek Miller, Alexander Streltsov
Many applications of the emerging quantum technologies, such as quantum teleportation and quantum key distribution, require singlets, maximally entangled states of two quantum bits. It is thus of utmost importance to develop optimal procedures for establishing singlets between remote parties. As has been shown very recently, singlets can be obtained from other quantum states by using a quantum catalyst
-
Dissipation as a resource for Quantum Reservoir Computing Quantum (IF 6.4) Pub Date : 2024-03-20 Antonio Sannia, Rodrigo Martínez-Peña, Miguel C. Soriano, Gian Luca Giorgi, Roberta Zambrini
Dissipation induced by interactions with an external environment typically hinders the performance of quantum computation, but in some cases can be turned out as a useful resource. We show the potential enhancement induced by dissipation in the field of quantum reservoir computing introducing tunable local losses in spin network models. Our approach based on continuous dissipation is able not only
-
Constant-sized self-tests for maximally entangled states and single projective measurements Quantum (IF 6.4) Pub Date : 2024-03-21 Jurij Volčič
Self-testing is a powerful certification of quantum systems relying on measured, classical statistics. This paper considers self-testing in bipartite Bell scenarios with small number of inputs and outputs, but with quantum states and measurements of arbitrarily large dimension. The contributions are twofold. Firstly, it is shown that every maximally entangled state can be self-tested with four binary
-
Classical shadows based on locally-entangled measurements Quantum (IF 6.4) Pub Date : 2024-03-21 Matteo Ippoliti
We study classical shadows protocols based on randomized measurements in $n$-qubit entangled bases, generalizing the random Pauli measurement protocol ($n = 1$). We show that entangled measurements ($n\geq 2$) enable nontrivial and potentially advantageous trade-offs in the sample complexity of learning Pauli expectation values. This is sharply illustrated by shadows based on two-qubit Bell measurements:
-
Beyond-adiabatic Quantum Admittance of a Semiconductor Quantum Dot at High Frequencies: Rethinking Reflectometry as Polaron Dynamics Quantum (IF 6.4) Pub Date : 2024-03-21 L. Peri, G. A. Oakes, L. Cochrane, C. J. B. Ford, M. F. Gonzalez-Zalba
Semiconductor quantum dots operated dynamically are the basis of many quantum technologies such as quantum sensors and computers. Hence, modelling their electrical properties at microwave frequencies becomes essential to simulate their performance in larger electronic circuits. Here, we develop a self-consistent quantum master equation formalism to obtain the admittance of a quantum dot tunnel-coupled
-
Critical enhancement of the spin Hall effect by spin fluctuations npj Quant. Mater. (IF 5.7) Pub Date : 2024-03-19 Satoshi Okamoto, Naoto Nagaosa
-
High flux strontium atom source Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-03-19 C-H Feng, P Robert, P Bouyer, B Canuel, J Li, S Das, C C Kwong, D Wilkowski, M Prevedelli, A Bertoldi
We present a novel cold strontium atom source designed for quantum sensors. We optimized the deceleration process to capture a large velocity class of atoms emitted from an oven and achieved a compact and low-power setup capable of generating a high atomic flux. Our approach involves velocity-dependent transverse capture of atoms using a two-dimensional magneto-optical trap. To enhance the atomic flux
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
Avoiding barren plateaus in the variational determination of geometric entanglement Quantum Sci. Technol. (IF 6.7) Pub Date : 2024-02-29 L Zambrano, A D Muñoz-Moller, M Muñoz, L Pereira, A Delgado
The barren plateau (BP) phenomenon is one of the main obstacles to implementing variational quantum algorithms in the current generation of quantum processors. Here, we introduce a method capable of avoiding the BP phenomenon in the variational determination of the geometric measure of entanglement for a large number of qubits. The method is based on measuring compatible two-qubit local functions whose
-
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
-
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
-
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
-
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