Article
Optics
C. H. Baldwin, B. J. Bjork, M. Foss-Feig, J. P. Gaebler, D. Hayes, M. G. Kokish, C. Langer, J. A. Sedlacek, D. Stack, G. Vittorini
Summary: By combining the advantages of the Molmer-Sorensen gate and the light-shift gate, a technique has been developed to operate the light-shift gate directly on hyperfine clock states with high gate fidelity achieved through small detuning from optical transition. Further improvements in gate fidelity above 99.99% are suggested through theoretical modeling.
Article
Materials Science, Multidisciplinary
Benoit Voisin, Joseph Salfi, Rajib Rahman, Sven Rogge
Summary: Silicon is a leading qubit platform due to its exceptional coherence times and available commercial manufacturing integration platform. Accurate quantum state manipulation is crucial for building scalable quantum processing architectures, which requires a complete understanding of the underlying quantum state properties. This article reviews electrical methods developed for probing the quantum states encoded in individual and interacting atom qubits in silicon, including single electron-tunneling spectroscopy, radio frequency reflectometry, and scanning tunneling microscopy.
Article
Physics, Multidisciplinary
Preeti Sharma, Sakshi Rao, Bhaskar Kanseri
Summary: In this article, we demonstrate the generation of partially spatially coherent qubits in a spontaneous parametric down-conversion (SPDC) process using a Gaussian Schell model (GSM) pump beam. We experimentally transfer the spatial coherence features of the pump to the biphotons field and observe the spatial profiles and multi-mode nature of partially coherent qubits generated in type-I and type-II non-collinear SPDC process. These findings are important for the efficient generation of partially spatially coherent qubits and have wide applications in areas such as quantum cryptography, teleportation, imaging, and lithography.
Article
Physics, Multidisciplinary
Xinxin Cai, Elliot J. Connors, Lisa F. Edge, John M. Nichol
Summary: Electron spins in silicon quantum dots are excellent qubits due to their long coherence times, high gate fidelities, and compatibility with advanced semiconductor manufacturing techniques. In this study, we demonstrate that spin-valley coupling in Si enables coherent control of single and multi-electron spin states without oscillating electromagnetic fields. Our results establish spin-valley coupling as a promising mechanism for coherent control of qubits based on electron spins in semiconductor quantum dots.
Article
Quantum Science & Technology
Federico Fedele, Anasua Chatterjee, Saeed Fallahi, Geoffrey C. Gardner, Michael J. Manfra, Ferdinand Kuemmeth
Summary: Researchers demonstrated a two-by-two array of four singlet-triplet qubits in gallium arsenide, showing simultaneous coherent operations and four-qubit measurements via exchange oscillations and frequency-multiplexed single-shot measurements. A larger multielectron quantum dot is fabricated in the center of the array as a tunable interqubit link, which is utilized to demonstrate coherent spin exchange with selected qubits. These techniques can be extended to other materials, showing a path towards quantum processors with gate-controlled spin qubits.
Article
Optics
Qi-Ping Su, Yu Zhang, Chui-Ping Yang
Summary: This study proposes a one-step implementation of a multi-target qubit controlled-NOT gate, where a superconducting qubit controls multiple cat-state qubits simultaneously. The gate operation is simple, quick, and independent of the number of target qubits.
Article
Physics, Multidisciplinary
Teresa Hoenigl-Decrinis, Ilya Antonov, Rais Shaikhaidarov, Kyung Ho Kim, Vladimir N. Antonov, Oleg Astafiev
Summary: We demonstrate the capacitive coupling of coherent quantum phase slip (CQPS) flux qubits to a resonator. Our results show that the coupling strength does not depend on the qubit's energy, which provides flexibility in material and design choices for CQPS-based devices. This is the first report of CQPS in TiN and the first demonstration of capacitive coupling of a CQPS flux qubit.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Tim Menke, William P. Banner, Thomas R. Bergamaschi, Agustin Di Paolo, Antti Vepsalainen, Steven J. Weber, Roni Winik, Alexander Melville, Bethany M. Niedzielski, Danna Rosenberg, Kyle Serniak, Mollie E. Schwartz, Jonilyn L. Yoder, Alan Aspuru-Guzik, Simon Gustavsson, Jeffrey A. Grover, Cyrus F. Hirjibehedin, Andrew J. Kerman, William D. Oliver
Summary: This study presents a superconducting circuit architecture that enables two-local and three-local interactions between three flux qubits through a designed coupling module. The system Hamiltonian is estimated using multiqubit pulse sequences implementing Ramsey-type interferometry. The three-local interaction can be coherently tuned over several MHz via the coupler flux biases and can also be turned off. This research has significant applications in quantum annealing, analog quantum simulation, and gate-model quantum computation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Katrina Barnes, Peter Battaglino, Benjamin J. Bloom, Kayleigh Cassella, Robin Coxe, Nicole Crisosto, Jonathan P. King, Stanimir S. Kondov, Krish Kotru, Stuart C. Larsen, Joseph Lauigan, Brian J. Lester, Mickey McDonald, Eli Megidish, Sandeep Narayanaswami, Ciro Nishiguchi, Remy Notermans, Lucas S. Peng, Albert Ryou, Tsung-Yao Wu, Michael Yarwood
Summary: This study introduces a qubit encoded in the nuclear spin states of a single Sr-87 atom and demonstrates long coherence time in a register of individually-controlled qubits. The researchers achieve comparable coherence times while driving multiple qubits in parallel. They suggest that nuclear spin qubits will combine with technical advances to accelerate the realization of intermediate-scale quantum information processors.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Aaron J. Weinstein, Matthew D. Reed, Aaron M. Jones, Reed W. Andrews, David Barnes, Jacob Z. Blumoff, Larken E. Euliss, Kevin Eng, Bryan H. Fong, Sieu D. Ha, Daniel R. Hulbert, Clayton A. C. Jackson, Michael Jura, Tyler E. Keating, Joseph Kerckhoff, Andrey A. Kiselev, Justine Matten, Golam Sabbir, Aaron Smith, Jeffrey Wright, Matthew T. Rakher, Thaddeus D. Ladd, Matthew G. Borselli
Summary: This study demonstrates an alternative approach to quantum computation that uses energy-degenerate encoded qubit states controlled by nearest-neighbour contact interactions, bypassing microwave-associated correlated errors. The combination of enriched silicon, all-electrical partial swap operations, and configurable encoding offers a strong pathway towards scalable fault tolerance and computational advantage.
Article
Quantum Science & Technology
Amor Gueddana, Vasudevan Lakshminarayanan
Summary: We propose a Controlled-Controlled-phase gate (CCZ) using three atoms trapped in separate optical cavities and connected by two optical fibers. We analyze the Hamiltonian of the atom-cavity-fiber system and provide Hamiltonian matrix expressions for different initial states. We study the fidelity of the gate and show that it can reach 99.28%, considering the impact of physical parameters and factors such as spontaneous emission and photon leakage.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Physics, Multidisciplinary
Philip D. Gregory, Jacob A. Blackmore, Sarah L. Bromley, Jeremy M. Hutson, Simon L. Cornish
Summary: Quantum states with long-lived coherence are crucial for quantum computation, simulation, and metrology. By characterizing and eliminating the dominant mechanisms of decoherence in ultracold molecular qubits, we achieved coherence times exceeding 5.6 seconds.
Article
Materials Science, Multidisciplinary
Guo Xuan Chan, J. P. Kestner, Xin Wang
Summary: Theoretically, a range of nearly sweet spots appears in the coupled singlet-triplet qubit system when a strong enough external magnetic field is applied. Ramping to and from the judiciously chosen nearly sweet spot using sequences based on the shortcut to adiabaticity offers maximal gate fidelities under charge noise and phonon-induced decoherence, facilitating realization of high-fidelity two-qubit gates in singlet-triplet qubit systems.
Article
Quantum Science & Technology
Stefano Bosco, Bence Hetenyi, Daniel Loss
Summary: Hole Si fin field-effect transistors (FinFETs) are shown to be highly compatible with modern CMOS technology and have operational sweet spots where charge noise is completely removed. The presence of these sweet spots is a result of the interplay between material anisotropy and the shape of the FinFET cross section. Designs that maximize qubit performance and potentially pave the way towards a scalable spin-based quantum computer are identified.
Article
Physics, Multidisciplinary
Boris O. Volkov, Oleg Morzhin, Alexander N. Pechen
Summary: The mathematical analysis of quantum control landscapes is crucial in determining the absence or presence of traps in quantum control objectives. In this study, a rigorous analysis of control landscapes for ultrafast generation of single-qubit quantum gates was conducted, showing that the control landscape for ultrafast phase shift gate generation is trap-free using a combination of analytical methods and numerical optimization techniques.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Optics
Shaul Mukamel, Matthias Freyberger, Wolfgang Schleich, Marco Bellini, Alessandro Zavatta, Gerd Leuchs, Christine Silberhorn, Robert W. Boyd, Luis Lorenzo Sanchez-Soto, Andre Stefanov, Marco Barbieri, Anna Paterova, Leonid Krivitsky, Sharon Shwartz, Kenji Tamasaku, Konstantin Dorfman, Frank Schlawin, Vahid Sandoghdar, Michael Raymer, Andrew Marcus, Oleg Varnavski, Theodore Goodson, Zhi-Yuan Zhou, Bao-Sen Shi, Shahaf Asban, Marlan Scully, Girish Agarwal, Tao Peng, Alexei Sokolov, Zhe-Dong Zhang, M. Suhail Zubairy, Ivan A. Vartanyants, Elena del Valle, Fabrice Laussy
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2020)
Article
Physics, Multidisciplinary
F. Albarelli, M. Barbieri, M. G. Genoni, I Gianani
Article
Physics, Applied
Valeria Cimini, Marco G. Genoni, Ilaria Gianani, Nicolo Spagnolo, Fabio Sciarrino, Marco Barbieri
PHYSICAL REVIEW APPLIED
(2020)
Article
Quantum Science & Technology
Valeria Cimini, Ilaria Gianani, Fabrizio Piacentini, Ivo Pietro Degiovanni, Marco Barbieri
QUANTUM SCIENCE AND TECHNOLOGY
(2020)
Article
Engineering, Electrical & Electronic
Ilaria Gianani, Marco G. Genoni, Marco Barbieri
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2020)
Article
Physics, Multidisciplinary
Valeria Cimini, Marco Barbieri, Nicolas Treps, Mattia Walschaers, Valentina Parigi
PHYSICAL REVIEW LETTERS
(2020)
Article
Quantum Science & Technology
V Cimini, S. Gherardini, M. Barbieri, I Gianani, M. Sbroscia, L. Buffoni, M. Paternostro, F. Caruso
NPJ QUANTUM INFORMATION
(2020)
Article
Physics, Applied
Valeria Cimini, Emanuele Polino, Mauro Valeri, Ilaria Gianani, Nicolo Spagnolo, Giacomo Corrielli, Andrea Crespi, Roberto Osellame, Marco Barbieri, Fabio Sciarrino
Summary: Calibrating sensors is a crucial step in validating their functionality, and machine learning offers a convenient solution by mapping parameters to device responses. This study demonstrates the use of a neural network algorithm for calibrating integrated photonic devices depending on two parameters, showing that reliable characterization is achievable with careful network training. The approach proves to be versatile and promising for mass production, as the same neural network can calibrate different devices with similar attributes.
PHYSICAL REVIEW APPLIED
(2021)
Letter
Optics
Ilaria Gianani, Francesco Albarelli, Adriano Verna, Valeria Cimini, Rafal Demkowicz-Dobrzanski, Marco Barbieri
Summary: Phase measurements are crucial in quantum optical sensing, but the Heisenberg scaling is weakened in the presence of noise and loss. Studies show that in systems with large photon numbers, phase and absorption profiles are connected by Kramers-Kronig relations, highlighting the impact of loss measurements on phase profiles.
Article
Optics
Valeria Cimini, Francesco Albarelli, Ilaria Gianani, Marco Barbieri
Summary: In this study, we apply the theory of semiparametric estimation to assess the parameters of interest in a Hong-Ou-Mandel interference experiment involving a spectrally entangled two-photon state. Specifically, we focus on estimating the Hermite-Gauss components of the marginal symmetrized wave function, which are shown to serve as an entanglement witness for the two-photon state.
Article
Optics
Ilaria Gianani, Francesco Albarelli, Valeria Cimini, Marco Barbieri
Summary: This article presents an experimental quantum-enhanced function estimation of the optical response of a liquid crystal, highlighting the importance of optimizing resource utilization to access the rich information contained in continuous signals. The results show that quantum advantage becomes substantial only past a certain sampling density, depending on the interpolation method and the function at hand.
Article
Physics, Multidisciplinary
Luca Mancino, Marco G. Genoni, Marco Barbieri, Mauro Paternostro
PHYSICAL REVIEW RESEARCH
(2020)
Article
Optics
V Cimini, I Gianani, M. F. Sacchi, C. Macchiavello, M. Barbieri
Proceedings Paper
Engineering, Electrical & Electronic
Valeria Cimini, Ludovica Ruggiero, Ilaria Gianani, Marco Sbroscia, Tecla Gasperi, Emanuele Roccia, Luca Mancino, Daniela Tofani, Fabio Bruni, Maria Antonietta Ricci, Marco Barbieri
2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2019)
Article
Optics
Michele M. Feyles, Luca Mancino, Marco Sbroscia, Ilaria Gianani, Marco Barbieri
