Articles

Universal set of quantum gates for the flip-flop qubit in the presence of 1/f noise

Impurities hosted in semiconducting solid matrices represent an extensively studied platform for quantum computing applications. In this scenario, the so-called flip-flop qubit emerges as a convenient choice f...

Authors: Elena Ferraro, Davide Rei, Matteo Paris and Marco De Michielis

Engineering the microwave to infrared noise photon flux for superconducting quantum systems

Electromagnetic filtering is essential for the coherent control, operation and readout of superconducting quantum circuits at milliKelvin temperatures. The suppression of spurious modes around transition frequ...

Authors: Sergey Danilin, João Barbosa, Michael Farage, Zimo Zhao, Xiaobang Shang, Jonathan Burnett, Nick Ridler, Chong Li and Martin Weides

Deep reinforcement learning for universal quantum state preparation via dynamic pulse control

Accurate and efficient preparation of quantum state is a core issue in building a quantum computer. In this paper, we investigate how to prepare a certain single- or two-qubit target state from arbitrary initi...

Authors: Run-Hong He, Rui Wang, Shen-Shuang Nie, Jing Wu, Jia-Hui Zhang and Zhao-Ming Wang

Proof-of-principle demonstration of semi-quantum key distribution based on the Mirror protocol

Semi-quantum key distribution (SQKD) is used to establish a string of shared secret keys between a quantum party and a classical party. Here, we report the first proof-of-principle experimental demonstration o...

Authors: Siyu Han, Yutao Huang, Shang Mi, Xiaojuan Qin, Jindong Wang, Yafei Yu, Zhengjun Wei and Zhiming Zhang

Quantum anonymous collision detection for quantum networks

Quantum mechanics offers new opportunities for diverse information processing tasks in communication and computational networks. In the last two decades, the notion of quantum anonymity has been introduced in ...

Authors: Awais Khan, Uman Khalid, Junaid ur Rehman, Kyesan Lee and Hyundong Shin

Airborne quantum key distribution with boundary layer effects

With the substantial progress of terrestrial fiber-based quantum networks and satellite-based quantum nodes, airborne quantum key distribution (QKD) is now becoming a flexible bond between terrestrial fiber an...

Authors: Hui-Cun Yu, Bang-Ying Tang, Huan Chen, Yang Xue, Jie Tang, Wan-Rong Yu, Bo Liu and Lei Shi

Industry quantum computing applications

Quantum computing promises to overcome computational limitations with better and faster solutions for optimization, simulation, and machine learning problems. Europe and Germany are in the process of successfu...

Authors: Andreas Bayerstadler, Guillaume Becquin, Julia Binder, Thierry Botter, Hans Ehm, Thomas Ehmer, Marvin Erdmann, Norbert Gaus, Philipp Harbach, Maximilian Hess, Johannes Klepsch, Martin Leib, Sebastian Luber, Andre Luckow, Maximilian Mansky, Wolfgang Mauerer…

Quantum technology for military applications

Quantum technology is an emergent and potentially disruptive discipline, with the ability to affect many human activities. Quantum technologies are dual-use technologies, and as such are of interest to the def...

Authors: Michal Krelina

A low-noise single-photon detector for long-distance free-space quantum communication

We build and test a single-photon detector based on a Si avalanche photodiode Excelitas 30902SH thermoelectrically cooled to −100^∘C. Our detector has dark count rate below 1 Hz, ...

Authors: Elena Anisimova, Dmitri Nikulov, Simeng Simone Hu, Mark Bourgon, Sebastian Philipp Neumann, Rupert Ursin, Thomas Jennewein and Vadim Makarov

Impact of receiver imbalances on the security of continuous variables quantum key distribution

Continuous-variable quantum key distribution (CV-QKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users in a communication network. However, the practical devices ...

Authors: Daniel Pereira, Margarida Almeida, Margarida Facão, Armando N. Pinto and Nuno A. Silva

Phase sensitivity of an \(\operatorname{SU}(1,1)\) interferometer via product detection

Authors: Qingle Wang, Yami Fang, Xiaoping Ma and Dong Li

SpinQ Gemini: a desktop quantum computing platform for education and research

SpinQ Gemini is a commercial desktop quantum computing platform designed and manufactured by SpinQ Technology. It is an integrated hardware-software system. The first generation product with two qubits was lau...

Authors: Shi-Yao Hou, Guanru Feng, Zipeng Wu, Hongyang Zou, Wei Shi, Jinfeng Zeng, Chenfeng Cao, Sheng Yu, Zikai Sheng, Xin Rao, Bing Ren, Dawei Lu, Junting Zou, Guoxing Miao, Jingen Xiang and Bei Zeng

Quantum technologies in the telecommunications industry

Quantum based technologies have been fundamental in our world. After producing the laser and the transistor, the devices that have shaped our modern information society, the possibilities enabled by the abilit...

Authors: Vicente Martin, Juan Pedro Brito, Carmen Escribano, Marco Menchetti, Catherine White, Andrew Lord, Felix Wissel, Matthias Gunkel, Paulette Gavignet, Naveena Genay, Olivier Le Moult, Carlos Abellán, Antonio Manzalini, Antonio Pastor-Perales, Victor López and Diego López

Accelerating quantum computer developments

Given the recent breakthroughs in quantum technology development in R& D labs all over the world, the perspective of high-tech companies has changed. Product development is initiated next to the existing research

Authors: Garrelt J. N. Alberts, M. Adriaan Rol, Thorsten Last, Benno W. Broer, Cornelis C. Bultink, Matthijs S. C. Rijlaarsdam and Amber E. Van Hauwermeiren

Correction to: Benchmarking machine learning algorithms for adaptive quantum phase estimation with noisy intermediate-scale quantum sensors

Authors: Nelson Filipe Costa, Yasser Omar, Aidar Sultanov and Gheorghe Sorin Paraoanu

Benchmarking machine learning algorithms for adaptive quantum phase estimation with noisy intermediate-scale quantum sensors

Quantum phase estimation is a paradigmatic problem in quantum sensing and metrology. Here we show that adaptive methods based on classical machine learning algorithms can be used to enhance the precision of qu...

Authors: Nelson Filipe Costa, Yasser Omar, Aidar Sultanov and Gheorghe Sorin Paraoanu

A low cost, short range quantum key distribution system

We present a miniaturized quantum key distribution system, designed to augment the more mature quantum key distribution systems currently commercially available. Our device is designed for the consumer market,...

Authors: David Lowndes, Stefan Frick, Andy Hart and John Rarity

Towards security recommendations for public-key infrastructures for production environments in the post-quantum era

Quantum computing technologies pose a significant threat to the currently employed public-key cryptography protocols. In this paper, we discuss the impact of the quantum threat on public key infrastructures (P...

Authors: Sergey E. Yunakovsky, Maxim Kot, Nikolay Pozhar, Denis Nabokov, Mikhail Kudinov, Anton Guglya, Evgeniy O. Kiktenko, Ekaterina Kolycheva, Alexander Borisov and Aleksey K. Fedorov

Repeated radiation damage and thermal annealing of avalanche photodiodes

Avalanche photodiodes (APDs) are well-suited for single-photon detection on quantum communication satellites as they are a mature technology with high detection efficiency without requiring cryogenic cooling. ...

Authors: Ian DSouza, Jean-Philippe Bourgoin, Brendon L. Higgins, Jin Gyu Lim, Ramy Tannous, Sascha Agne, Brian Moffat, Vadim Makarov and Thomas Jennewein

Qualifying quantum approaches for hard industrial optimization problems. A case study in the field of smart-charging of electric vehicles

In order to qualify quantum algorithms for industrial NP-Hard problems, comparing them to available polynomial approximate classical algorithms and not only to exact exponential ones is necessary. This is a gr...

Authors: Constantin Dalyac, Loïc Henriet, Emmanuel Jeandel, Wolfgang Lechner, Simon Perdrix, Marc Porcheron and Margarita Veshchezerova

Optimal collection of radiation emitted by a trapped atomic ensemble

Trapped atomic ensembles are convenient systems for quantum information storage in the long-lived sublevels of the electronic ground state and its conversion to propagating optical photons via stimulated Raman...

Authors: Árpád Kurkó, Peter Domokos, András Vukics, Thomas Bækkegaard, Nikolaj Thomas Zinner, József Fortágh and David Petrosyan

Detecting factorization effect in continuous-time quantum walks

We consider an continuous-time quantum walk on triple graphs with a potential well in one of the terminal sites on the main chain and study its dynamical properties in the open system by introducing a ‘spontan...

Authors: Jin-Hui Zhu, Li-Hua Lu and You-Quan Li

Hierarchical-environment-assisted non-Markovian and its effect on thermodynamic properties

We consider a microscopic collision model, i.e., a quantum system interacts with a hierarchical environment consisting of an auxiliary system and a reservoir. We show how the non-Markovian character of the sys...

Authors: Yongwei Li and Lei Li

Simultaneous imaging of magnetic field and temperature using a wide-field quantum diamond microscope

Quantum sensing based on nitrogen-vacancy centers in diamond has shown excellent properties. Combined with the imaging technique, it shows exciting practicability. Here, we demonstrate the simultaneously imagi...

Authors: Yulei Chen, Zhonghao Li, Hao Guo, Dajin Wu and Jun Tang

Optomechanically induced transparency, amplification, and Fano resonance in a multimode optomechanical system with quadratic coupling

We explore the optical response of a multimode optomechanical system with quadratic coupling to a weak probe field, where the cavity is driven by a strong control field and the two movable membranes are, respe...

Authors: Yongchao Zhang, Zhipeng Zhu, Yuanshun Cui, Hualing Yu, Cheng Jiang and Xiufeng Cao

Startup Qilimanjaro—towards a European full-stack coherent quantum annealer platform

Qilimanjaro Quantum Tech is the full-stack quantum spin-off of three research institutions, the Barcelona Supercomputing Center (BSC), the Institute for High Energy Physics (IFAE) and the University of Barcelo...

Authors: V. Canivell, P. Forn-Díaz, A. Garcia-Saez and R. Sagastizabal

Path to European quantum unicorns

Quantum computing holds the potential to deliver great economic prosperity to the European Union (EU). However, the creation of successful business in the field is challenging owing to the required extensive i...

Authors: Markku Räsänen, Henrikki Mäkynen, Mikko Möttönen and Jan Goetz

Exploiting the wide dynamic range of silicon photomultipliers for quantum optics applications

Silicon photomultipliers are photon-number-resolving detectors endowed with hundreds of cells enabling them to reveal high-populated quantum optical states. In this paper, we address such a goal by showing the...

Authors: Silvia Cassina, Alessia Allevi, Valerio Mascagna, Michela Prest, Erik Vallazza and Maria Bondani

Anomalous diffraction of matter waves with minimal quantum metasurfaces

In the last few years, there is a huge upsurge in the number of closed deals regarding quantum technologies for materials, computing, communication and instrumentation. Such a trend has inevitably affected the...

Authors: Constantinos Valagiannopoulos

Commercial applications of quantum computing

Despite the scientific and engineering challenges facing the development of quantum computers, considerable progress is being made toward applying the technology to commercial applications. In this article, we...

Authors: Francesco Bova, Avi Goldfarb and Roger G. Melko

The Bose-Einstein Condensate and Cold Atom Laboratory

Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension and eliminates the gravitational sag for trapped...

Authors: Kai Frye, Sven Abend, Wolfgang Bartosch, Ahmad Bawamia, Dennis Becker, Holger Blume, Claus Braxmaier, Sheng-Wey Chiow, Maxim A. Efremov, Wolfgang Ertmer, Peter Fierlinger, Tobias Franz, Naceur Gaaloul, Jens Grosse, Christoph Grzeschik, Ortwin Hellmig…

A study to develop a robust method for measuring the detection efficiency of free-running InGaAs/InP single-photon detectors

The challenges faced in a comparison of measuring the detection efficiency of free-running InGaAs/InP single-photon avalanche detectors (InGaAs/InP SPAD) were studied by four European National Metrology Instit...

Authors: M. López, A. Meda, G. Porrovecchio, R. A. Starkwood (Kirkwood), M. Genovese, G. Brida, M. Šmid, C. J. Chunnilall, I. P. Degiovanni and S. Kück

A biocompatible technique for magnetic field sensing at (sub)cellular scale using Nitrogen-Vacancy centers

Authors: Ettore Bernardi, Ekaterina Moreva, Paolo Traina, Giulia Petrini, Sviatoslav Ditalia Tchernij, Jacopo Forneris, Željko Pastuović, Ivo Pietro Degiovanni, Paolo Olivero and Marco Genovese

OPM magnetorelaxometry in the presence of a DC bias field

Spatial quantitative information about magnetic nanoparticle (MNP) distributions is a prerequisite for biomedical applications like magnetic hyperthermia and magnetic drug targeting. This information can be ga...

Authors: Aaron Jaufenthaler, Volkmar Schultze, Theo Scholtes, Christian B. Schmidt, Michael Handler, Ronny Stolz and Daniel Baumgarten

A conformal array of microfabricated optically-pumped first-order gradiometers for magnetoencephalography

An array of 21 first-order gradiometers based on zero-field optically-pumped magnetometers is demonstrated for use in magnetoencephalography. Sensors are oriented radially with respect to the head and housed i...

Authors: N. V. Nardelli, A. R. Perry, S. P. Krzyzewski and S. A. Knappe

Enhanced Hanbury Brown and Twiss interferometry using parametric amplification

The Hanbury Brown and Twiss (HBT) interferometer was proposed to observe intensity correlations of starlight to measure a star’s angular diameter. As the intensity of light that reaches the detector from a sta...

Authors: Xiaoping Ma, Chenglong You, Sushovit Adhikari, Yongjian Gu, Omar S. Magaña-Loaiza, Jonathan P. Dowling and Hwang Lee

Second-order effects in parametric-resonance magnetometers based on atomic alignment

Optically-pumped magnetometers (OPM) based on parametric resonance allow real-time tri-axial measurement of very small magnetic fields with a single optical access to the gas cell. Most of these magnetometers ...

Authors: François Beato and Agustin Palacios-Laloy

A quantum key distribution protocol for rapid denial of service detection

We introduce a quantum key distribution protocol designed to expose fake users that connect to Alice or Bob for the purpose of monopolising the link and denying service. It inherently resists attempts to exhau...

Authors: Alasdair B. Price, John G. Rarity and Chris Erven

Niobium quarter-wave resonator with the optimized shape for quantum information systems

Quantum computers (QC), if realized, could disrupt many computationally intense fields of science. The building block element of a QC is a quantum bit (qubit). Qubits enable the use of quantum superposition an...

Authors: S. V. Kutsaev, K. Taletski, R. Agustsson, P. Carriere, A. N. Cleland, Z. A. Conway, É. Dumur, A. Moro and A. Yu. Smirnov

AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space

We propose in this White Paper a concept for a space experiment using cold atoms to search for ultra-light dark matter, and to detect gravitational waves in the frequency range between the most sensitive range...

Authors: Yousef Abou El-Neaj, Cristiano Alpigiani, Sana Amairi-Pyka, Henrique Araújo, Antun Balaž, Angelo Bassi, Lars Bathe-Peters, Baptiste Battelier, Aleksandar Belić, Elliot Bentine, José Bernabeu, Andrea Bertoldi, Robert Bingham, Diego Blas, Vasiliki Bolpasi, Kai Bongs…

Applying the matched-filter technique to the search for dark matter transients with networks of quantum sensors

There are several networks of precision quantum sensors in existence, including networks of atomic clocks, magnetometers, and gravitational wave detectors. These networks can be re-purposed for searches of exo...

Authors: Guglielmo Panelli, Benjamin M. Roberts and Andrei Derevianko

Scheduling of space to ground quantum key distribution

Satellite-based platforms are currently the only feasible way of achieving intercontinental range for quantum communication, enabling thus the future global quantum internet. Recent demonstrations by the Chine...

Authors: Mateusz Polnik, Luca Mazzarella, Marilena Di Carlo, Daniel KL Oi, Annalisa Riccardi and Ashwin Arulselvan

Sensing microwave photons with a Bose–Einstein condensate

We consider the interaction of a magnetically trapped Bose–Einstein condensate of Rubidium atoms with the stationary microwave radiation field sustained by a coplanar waveguide resonator. This coupling allows ...

Authors: Orsolya Kálmán and Peter Domokos

A similarity of quantum phase transition and quench dynamics in the Dicke model beyond the thermodynamic limit

We study the quantum phase transition in the Dicke model beyond the thermodynamic limit. With the Kibble–Zurek mechanism and adiabatic dynamics, we find that the residual energy is inversely proportional to th...

Authors: Lituo Shen, Zhicheng Shi, Zhenbiao Yang, Huaizhi Wu, Zhirong Zhong and Shibiao Zheng

Performance analysis of an optically pumped magnetometer in Earth’s magnetic field

We experimentally investigate the influence of the orientation of optically pumped magnetometers in Earth’s magnetic field. We focus our analysis to an operational mode that promises femtotesla field resolutio...

Authors: Gregor Oelsner, Volkmar Schultze, Rob IJsselsteijn and Ronny Stolz

Field trial of a three-state quantum key distribution scheme in the Florence metropolitan area

In-field demonstrations in real-world scenarios boost the development of a rising technology towards its integration in existing infrastructures. Although quantum key distribution (QKD) devices are already ado...

Authors: Davide Bacco, Ilaria Vagniluca, Beatrice Da Lio, Nicola Biagi, Adriano Della Frera, Davide Calonico, Costanza Toninelli, Francesco S. Cataliotti, Marco Bellini, Leif K. Oxenløwe and Alessandro Zavatta

Encrypted quantum correlations: delayed choice of quantum statistics and other applications

In a three-particle extension of Wheeler’s delayed choice gedanken experiment, the quantum statistics of two particles is undetermined until a third particle is measured. As a function of the measurement resul...

Authors: Manuel Gessner and Augusto Smerzi

Optomechanically induced transparency and nonlinear responses based on graphene optomechanics system

Due to its unique properties of low mass density, high frequency, high quality-factor and intrinsically small size, graphene has received significant attention and is considered as an ideal material for fabric...

Authors: Hua-Jun Chen

Engineering cryogenic setups for 100-qubit scale superconducting circuit systems

A robust cryogenic infrastructure in form of a wired, thermally optimized dilution refrigerator is essential for solid-state based quantum processors. Here, we engineer a cryogenic setup, which minimizes passi...

Authors: S. Krinner, S. Storz, P. Kurpiers, P. Magnard, J. Heinsoo, R. Keller, J. Lütolf, C. Eichler and A. Wallraff

Finding critical states of enhanced memory capacity in attractive cold bosons

We discuss a class of quantum theories which exhibit a sharply increased memory storage capacity due to emergent gapless degrees of freedom. Their realization, both theoretical and experimental, is of great in...

Authors: Gia Dvali, Marco Michel and Sebastian Zell