Article
Quantum Science & Technology
William Huie, Lintao Li, Neville Chen, Xiye Hu, Zhubing Jia, Won Kyu Calvin Sun, Jacob P. Covey
Summary: We demonstrate high-fidelity repetitive measurements of nuclear spin qubits in an array of neutral ytterbium-171 (171Yb) atoms. We combine our measurement technique with high-contrast rotations of the nuclear spin qubit to explore two paradigmatic scenarios. Furthermore, we employ real-time feedforward to repetitively and deterministically prepare the qubit in a specific direction.
Article
Instruments & Instrumentation
Leandro Stefanazzi, Kenneth Treptow, Neal Wilcer, Chris Stoughton, Collin Bradford, Sho Uemura, Silvia Zorzetti, Salvatore Montella, Gustavo Cancelo, Sara Sussman, Andrew Houck, Shefali Saxena, Horacio Arnaldi, Ankur Agrawal, Helin Zhang, Chunyang Ding, David Schuster
Summary: We introduce a Xilinx RFSoC-based qubit controller, called QICK, which supports direct synthesis of control pulses up to 6 GHz. The QICK can control multiple qubits or other quantum devices, with important digital latency for quantum error correction and feedback protocols. Benchmarking on a transmon qubit, an average gate fidelity of Favg=99.93% is achieved. All schematics, firmware, and software are open-source.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Materials Science, Multidisciplinary
Edyta N. Osika, Samuel K. Gorman, Serajum Monir, Yu-Ling Hsueh, Marcus Borscz, Helen Geng, Brandur Thorgrimsson, Michelle Y. Simmons, Rajib Rahman
Summary: Recent research has shown that high-fidelity readout of singlet-triplet qubits can be achieved in silicon-based multidonor quantum dot systems using shelving and latched readout techniques. Shelving readout requires a calibration step to account for time-varying nuclear spin polarization, while latched readout maintains non-zero readout visibility even in the presence of nuclear spin flips.
Article
Multidisciplinary Sciences
Qiang Li, Jun-Feng Wang, Fei-Fei Yan, Ji-Yang Zhou, Han-Feng Wang, He Liu, Li-Ping Guo, Xiong Zhou, Adam Gali, Zheng-Hao Liu, Zu-Qing Wang, Kai Sun, Guo-Ping Guo, Jian-Shun Tang, Hao Li, Li-Xing You, Jin-Shi Xu, Chuan-Feng Li, Guang-Can Guo
Summary: This study demonstrates the coherent manipulation of single divacancy spins in 4H-SiC with a high readout contrast and photon count rate, comparable to the nitrogen-vacancy centers in diamond. The coupling between a single defect spin and a nearby nuclear spin is also observed.
NATIONAL SCIENCE REVIEW
(2022)
Article
Physics, Applied
Claudio Bonizzoni, Mirco Tincani, Fabio Santanni, Marco Affronte
Summary: This article presents the application of machine learning in the control and readout of quantum qubits. By utilizing artificial neural networks to assist in the manipulation and readout of a molecular spin qubit, the experiments successfully tested amplitude and phase recognition.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
H. Koizumi, A. Ishikawa
Summary: This article theoretically considers the quantum gate control and readout of qubits composed of spin-vortex-induced loop currents (SVILCs) using external current feeding. Two types of SVILC qubit architectures are considered: one composed of stacked two-dimensional CuO2 bulk layers, and the other composed of CuO2 islands connected by artificial quantum dots. Qubit controls are achieved through the application of an external magnetic field and the feeding of external currents that cause Landau-Zener (LZ)-type transitions. The use of artificial quantum dot states for readout is also demonstrated.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2022)
Article
Multidisciplinary Sciences
F. Lecocq, F. Quinlan, K. Cicak, J. Aumentado, S. A. Diddams, J. D. Teufel
Summary: Introducing a photonic link using optical fiber enables delivering shot-noise-limited microwave signals directly at millikelvin temperatures for superconducting quantum information processing. The efficient delivery of coherent microwave control pulses via optical fiber provides a path towards a million-qubit universal quantum computer.
Article
Engineering, Electrical & Electronic
Benjamin Gys, Rohith Acharya, Steven Van Winckel, Kristiaan De Greve, Georges Gielen, Francky Catthoor
Summary: This paper presents a methodology for the co-design and co-simulation of silicon spin qubits and their associated cryo-CMOS circuitry. By integrating the model into a classical design flow, simulation of qubit readout is achieved, opening up opportunities for more robust design in the future.
IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS
(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
Engineering, Electrical & Electronic
Fabricio Alcalde Bessia, Troy England, Hongzhi Sun, Leandro Stefanazzi, Davide Braga, Miguel Sofo Haro, Shaorui Li, Juan Estrada, Farah Fahim
Summary: The MIDNA ASIC is a skipper-CCD readout chip capable of working at cryogenic temperatures. It integrates four front-end channels that process the CCD signal and performs differential averaging. Each channel consumes 4.5 mW power, has an input referred noise of 2.7 mu V-rms, and achieves sub-electron noise when coupled with a skipper-CCD.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2023)
Article
Engineering, Electrical & Electronic
Jongseok Park, Sushil Subramanian, Lester Lampert, Todor Mladenov, Ilya Klotchkov, Dileep J. Kurian, Esdras Juarez-Hernandez, Brando Perez Esparza, Sirisha Rani Kale, Asma K. T. Beevi, Shavindra P. Premaratne, Thomas P. Watson, Satoshi Suzuki, Mustafijur Rahman, Jaykant B. Timbadiya, Saksham Soni, Stefano Pellerano
Summary: This article presents a fully integrated Cryo-CMOS system on chip (SoC) for quantum computing, which includes an RF pulse modulator, a signal generator, a coherent receiver, and DACs. The SoC also integrates a microcontroller for low latency signal processing and increased flexibility in implementing quantum instruction sets.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2021)
Article
Engineering, Electrical & Electronic
Yatao Peng, Andrea Ruffino, Tsung-Yeh Yang, John Michniewicz, Miguel Fernando Gonzalez-Zalba, Edoardo Charbon
Summary: This article presents a cryo-CMOS receiver integrated with a frequency synthesizer for scalable multiplexed readout of qubits. It focuses on radio frequency (RF) reflectometry readout of silicon-based semiconductor spin qubits/quantum dots. The receiver includes a wideband low noise amplifier (LNA), a quadrature mixer, a complex filter, I/Q intermediate frequency amplifier chains, and a charge-pump phase-locked loop (PLL) with a programmable frequency divider. Circuit modifications and noise optimizations are applied for robust cryogenic temperature operation. The receiver demonstrates high gain, low noise figure, wide IF bandwidth, and good image rejection ratio.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2022)
Article
Engineering, Electrical & Electronic
S. J. Pauka, K. Das, R. Kalra, A. Moini, Y. Yang, M. Trainer, A. Bousquet, C. Cantaloube, N. Dick, G. C. Gardner, M. J. Manfra, D. J. Reilly
Summary: The study introduces a CMOS-based platform capable of generating multiple electrical signals for controlling qubits at 100 mK. By using on-chip circuit cells based on switched capacitors, the platform demonstrates the ability to generate static and dynamic voltages for parallel qubit control. Measurements show an average power dissipation of 18 nW per cell for generating 100 mV control pulses, suggesting potential scalability for a large system cooled by a commercially available dilution refrigerator.
NATURE ELECTRONICS
(2021)
Article
Optics
Quentin Ansel, Jonas Fischer, Dominique Sugny, Bruno Bellomo
Summary: This article discusses the optimal control of a qubit interacting with a structured environment. Using optimal control techniques, the researchers demonstrate the extent to which the qubit population and relaxation effects can be manipulated, and explore the selectivity problem of two uncoupled qubits.
Article
Physics, Applied
Michael Hanke, Carsten Richter, Felix Lange, Anna Reis, Julia Parker, Torsten Boeck
Summary: This study spatially investigates lattice spacing, twist, and bending in laterally (110)-oriented Ge nanowires using synchrotron-based scanning x-ray diffraction microscopy and numerical finite element calculations. The results reveal a complex relaxation scenario near the nucleation points of the nanowires, but overall the lattice compliance is preserved.
APPLIED PHYSICS LETTERS
(2022)
Review
Physics, Applied
Xuetao Gan, Dirk Englund, Dries Van Thourhout, Jianlin Zhao
Summary: Two-dimensional (2D) materials with layered structures have exceptional electronic and optical attributes, making them promising for various functions in light wave technology. In this study, we discuss state-of-the-art optical intensity modulators based on 2D materials, focusing on their operation spectral ranges determined by optical bandgaps. By leveraging the rich electronic structures and light-matter interactions of different 2D materials, we explore the working mechanisms and device architectures of modulators at specific wavelength ranges. These modulators have potential applications in fiber and chip optical communications, as well as chemical bond spectroscopy, free-space communications, and environment/health sensing.
APPLIED PHYSICS REVIEWS
(2022)
Article
Physics, Applied
Reginald Wilcox, Erik Eisenach, John Barry, Matthew Steinecker, Michael O'Keeffe, Dirk Englund, Danielle Braje
Summary: Quantum sensors based on spin defect ensembles have achieved rapid development by utilizing a nonoptical state preparation technique and microwave cavity readout technique, resulting in a nonoptical sensor architecture that is applicable to all solid-state paramagnetic defects with a zero-field splitting.
PHYSICAL REVIEW APPLIED
(2022)
Article
Quantum Science & Technology
Ashlesha Patil, Mihir Pant, Dirk Englund, Don Towsley, Saikat Guha
Summary: We developed a protocol for generating entanglement in the quantum internet that allows a repeater node to fuse successfully entangled links and maintain entanglement rate even as the distance increases. This powerful network property cannot be achieved with quantum networking protocols using Bell measurements and multiplexing alone. We also designed a two-party quantum key distribution protocol that converts shared entangled states into a shared secret, independent of distance.
NPJ QUANTUM INFORMATION
(2022)
Letter
Optics
Mark Dong, David Heim, Alex Witte, Genevieve Clark, Andrew J. Leenheer, Daniel Dominguez, Matthew Zimmermann, Y. Henry Wen, Gerald Gilbert, Dirk Englund, Matt Eichenfield
Summary: Visible-wavelength very large-scale integration photonic circuits have the potential to be important in quantum information and sensing technologies. This article reports a low-voltage optical phase shifter based on piezo-actuated mechanical cantilevers, demonstrating linear phase and amplitude modulation, low insertion loss, and high contrast.
Article
Multidisciplinary Sciences
Jordan Goldstein, Hongtao Lin, Skylar Deckoff-Jones, Marek Hempel, Ang-Yu Lu, Kathleen A. Richardson, Tomas Palacios, Jing Kong, Juejun Hu, Dirk Englund
Summary: This article discusses the importance of mid-infrared photonic integrated circuits (PICs) in sensing and optical communications, as well as the current limitation in operational wavelengths. The authors successfully developed photothermoelectric graphene photodetectors in a chalcogenide glass-on-CaF2 PIC, operating at 5.2 μm, showing promising results for gas sensing applications.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Applied
Ryan Hamerly, Saumil Bandyopadhyay, Dirk Englund
Summary: In this study, a new configuration algorithm is proposed to overcome the limitations of rectangular mesh interferometers in terms of fabrication errors and reduce the impact of errors on the performance of the interferometer. The algorithm is robust, requires no prior knowledge of process variations, and relies only on external sources and detectors.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Ryan Hamerly, Saumil Bandyopadhyay, Dirk Englund
Summary: This paper highlights the importance of algorithmic stability in self-configuration and proposes a self-configuration scheme for both triangular and rectangular meshes.
PHYSICAL REVIEW APPLIED
(2022)
Article
Quantum Science & Technology
Yuan Lee, Eric Bersin, Axel Dahlberg, Stephanie Wehner, Dirk Englund
Summary: The past decade has seen significant progress in experimentally realizing the building blocks of quantum repeaters. A quantum router architecture comprising many quantum memories connected in a photonic switchboard has been proposed to maintain entanglement fidelity over long-distance links and improve entanglement distribution rates. This architecture enables channel-loss-invariant fidelity and automatically prioritizes entanglement flows across the network, without requiring global network information.
NPJ QUANTUM INFORMATION
(2022)
Article
Optics
Rui Tang, Makoto Okano, Kasidit Toprasertpong, Shinichi Takagi, Dirk Englund, Mitsuru Takenaka
Summary: This study proposes a novel photonic integrated circuit (PIC) architecture for accelerated matrix multiplication, addressing the issue of hardware errors increasing with device scale in previous architectures. Additionally, a PIC architecture for general matrix-matrix multiplication (GEMM) is developed to enable high-energy efficiency computing on photonic chips.
Article
Nanoscience & Nanotechnology
Jasvith Raj Basani, Sri Krishna Vadlamani, Saumil Bandyopadhyay, Dirk R. R. Englund, Ryan Hamerly
Summary: This paper presents a novel architecture for multiport interferometers based on the sine-cosine fractal decomposition of a unitary matrix. The unique self-similarity and modularity of our design offer improved resilience to hardware imperfections compared to conventional multiport interferometers. Numerical simulations show that truncation of these meshes gives robust performance even under large fabrication errors, making it a significant advancement in large-scale programmable photonics for practical machine learning and quantum computing applications.
Article
Nanoscience & Nanotechnology
Laura Kim, Hyeongrak Choi, Matthew E. E. Trusheim, Hanfeng Wang, Dirk R. R. Englund
Summary: Nitrogen vacancy centers in diamond provide a spin-based qubit system with long coherence time even at room temperature, making them suitable ambient-condition quantum sensors for quantities including electromagnetic fields, temperature, and rotation. The optically addressable level structures of NV spins allow transduction of spin information onto light-field intensity. The sub-optimal readout fidelity of conventional fluorescence measurement remains a significant drawback for room-temperature ensemble sensing. Here, we discuss nanophotonic interfaces that provide opportunities to achieve near-unity readout fidelity based on IR absorption via resonantly enhanced spin-optic coupling. Spin-coupled resonant nanophotonic devices are projected to particularly benefit applications that utilize micro- to nanoscale sensing volume and to outperform present methods in their volume-normalized sensitivity.
Article
Multidisciplinary Sciences
Hanfeng Wang, Matthew E. Trusheim, Laura Kim, Hamza Raniwala, Dirk R. Englund
Summary: This study proposes a programmable architecture based on diamond color centers driven by electric or strain fields, aiming to reduce power consumption and cross-talk constraints in large-scale quantum networks. By densely packing diamond color centers in a programmable electrode array and driving quantum gates with electric or strain fields, this 'field programmable spin array’ (FPSA) enables high-speed control of individual color centers with low cross-talk and power dissipation. Integrated with a slow-light waveguide for efficient optical coupling, the FPSA serves as a quantum interface for optically-mediated entanglement, showing increased entanglement generation rate scaling into the thousand-qubit regime.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Xiyuan Lu, Mingkang Wang, Feng Zhou, Mikkel Heuck, Wenqi Zhu, Vladimir A. Aksyuk, Dirk R. Englund, Kartik Srinivasan
Summary: The authors demonstrate a method for generating orbital angular momentum (OAM) using photonic crystal ring resonators, while maintaining high cavity quality factors (up to 10^6). By ejecting high angular momentum states of a whispering gallery mode (WGM) microresonator through a grating-assisted mechanism, a scalable and chip-integrated solution for OAM generation is achieved.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Uday Saha, James D. Siverns, John Hannegan, Mihika Prabhu, Qudsia Quraishi, Dirk Englund, Edo Waks
Summary: In this work, we demonstrate the routing of single photons from a trapped ion using a photonic integrated circuit. The emission of the ion is matched to the operating wavelength of the circuit through quantum frequency conversion. Programmable phase shifters are used to switch the single photons between output channels and achieve a 50:50 beam splitting condition. These results are important for programmable routing and entanglement distribution in large-scale quantum networks and distributed quantum computers.
PHYSICAL REVIEW APPLIED
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Alexander Sludds, Ryan Hamerly, Saumil Bandyopadhyay, Zhizhen Zhong, Zaijun Chen, Liane Bernstein, Manya Ghobadi, Dirk Englund
Summary: In this paper, we present experimental demonstrations of ultra-low power edge computing enabled by wavelength division multiplexed optical links and time-integrating optical receivers. The initial experiments show optical energy per MAC less than or similar to 10 fJ.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
