Article
Optics
Priya J. Nadkarni, Shayan Srinivasa Garani
Summary: The use of preshared entangled states in nonbinary entanglement-assisted stabilizer codes is essential for achieving better error correction capability in quantum communication channels. A novel design architecture of the syndrome computation unit for qudit stabilizer codes has been proposed using classical additive codes and gates. The proposed quantum error correction architectures are beneficial for developing high-density coded quantum memories for archival quantum storage.
Article
Quantum Science & Technology
Guohui Wang, Chunming Tang
Summary: This paper introduces several new constructions of optimal subsystem codes, which can generate a large number of optimal subsystem codes using these methods.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Quantum Science & Technology
Arun J. Moorthy, Lane G. Gunderman
Summary: Quantum computers require effective error-correcting codes and the use of qudits instead of qubits can reduce the number of particles that need to be controlled. This study demonstrates how to construct codes with specific parameters using the technique of local-dimension-invariant (LDI) codes, and further reduces the requirement for large local-dimensions by utilizing the structure of CSS codes.
QUANTUM INFORMATION PROCESSING
(2023)
Article
Quantum Science & Technology
Arpit Dua, Tomas Jochym-O'Connor, Guanyu Zhu
Summary: In this study, the performance of fractal surface codes as fault-tolerant quantum memories is investigated. Decoding strategies for bit-flip and phase-flip errors in these codes are proven to exist. The sweep decoder, originally designed for regular 3D surface codes, is successfully adapted to the fractal surface codes by making suitable modifications on the boundaries. The minimum-weight-perfect-matching (MWPM) decoder is employed for phase-flip errors. The results show sustainable fault-tolerant threshold and code capacity threshold for specific fractal surface codes.
Article
Mathematics, Applied
Guohui Wang, Chunming Tang
Summary: In this study, several new methods for constructing optimal subsystem codes are proposed based on classical encoding techniques, which can play a significant role in quantum error correction.
COMPUTATIONAL & APPLIED MATHEMATICS
(2022)
Article
Quantum Science & Technology
Guohui Wang, Chunming Tang, Weiming Wei
Summary: This paper proposes several classes of Hermitian self-orthogonal MDS codes with subcodes of arbitrary dimensions. By taking advantage of the special structure of these classic MDS codes, several new classes of optimal AQECCs are obtained. A large number of optimal AQECCs can be generated using the construction methods presented in this paper.
QUANTUM INFORMATION PROCESSING
(2023)
Article
Quantum Science & Technology
J. Lacalle, L. M. Pozo-Coronado, A. L. Fonseca de Oliveira
Summary: In this work, we demonstrate that quantum error correcting codes cannot fix isotropic errors, even without introducing new errors; for isotropic errors, if the correction circuit detects an error, the corrected logical m-qubit has uniform distribution and loses all computing information.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Multidisciplinary Sciences
Neereja Sundaresan, Theodore J. J. Yoder, Youngseok Kim, Muyuan Li, Edward H. H. Chen, Grace Harper, Ted Thorbeck, Andrew W. W. Cross, Antonio D. Corcoles, Maika Takita
Summary: Quantum error correction is a promising approach for achieving high fidelity quantum computations. In this study, we demonstrate fault-tolerant syndrome measurements and correction on superconducting qubits connected in a heavy-hexagon lattice. By encoding a logical qubit with distance three and implementing real-time feedback, we achieve low logical error rates for both matching and maximum likelihood decoders.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Giacomo Pantaleoni, Ben Q. Baragiola, Nicolas C. Menicucci
Summary: The researchers utilize subsystem decomposition to analyze the encoded logical information in CV cluster-state quantum computing with GKP states. They decompose squeezed-vacuum states and approximate GKP states to reveal their logical information, and quantify damage to the logical information in approximate GKP states teleported through noisy CV cluster states. This approach allows them to focus on the encoded qubit information despite the complexities of the full CV nature of the mode.
Article
Computer Science, Information Systems
Yannis Bousba, Travis Russell
Summary: The study presents a quantum analogue of the Ramsey theorem, showing that quantum channels on specific matrices have quantum graphs with certain structures. While most quantum graphs generated by channels exhibit specific structures, not all cases can be reformulated using stabilizer codes and specific channels to represent the Ramsey theorem.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2021)
Article
Multidisciplinary Sciences
Renyu Wang, Leonid P. Pryadko
Summary: Generalized bicycle codes are a type of quantum error-correcting code constructed from binary circulant matrices. They have linear distance scaling and low-weight stabilizer generators, which can potentially improve performance in the presence of measurement errors.
Article
Quantum Science & Technology
Priya J. Nadkarni, Shayan Srinivasa Garani
Summary: The paper presents a coding-theoretic framework for constructing entanglement-assisted stabilizer codes over qudits of dimension p(k), utilizing pre-shared entangled states between the encoder and decoder. Various contributions such as mathematical decomposition of qudits, properties of the code, analytical expression for minimum entangled subqudits, code construction procedure, and quantum coding bounds are discussed. The error correction capability of the code is shown to be enhanced through entanglement assistance, making it useful for coded quantum computing and communication systems over p(k)-dimensional qudits.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Quantum Science & Technology
Serap Sahinkaya, Adrian Korban, Deniz Ustun
Summary: This paper focuses on the construction of maximal entanglement-assisted quantum error correction (EAQEC) codes. The authors obtained all possible construction matrices of linear codes over the skew group ring F-4 (sic)(phi) G, where G represents cyclic and dihedral groups with finite orders. They also employed the virus optimization (VO) algorithm to speed up the computational search time. The study resulted in several good maximal EAQEC codes over the finite field F-4, some of which were also maximum distance separable (MDS) codes. The authors also provided counterexamples to theorems proposed in previous studies and improved the lower bounds of existing maximal EAQEC codes.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Computer Science, Information Systems
Nicolas Delfosse, Ben W. Reichardt, Krysta M. Svore
Summary: Extensive quantum error correction is necessary for useful computation on a noisy quantum computer. However, imperfect parity check measurements in this process may produce incorrect outcomes or additional faults. In this work, the authors demonstrate that fault-tolerant quantum error correction can be achieved with fewer measurements using a noise model, and discuss the relationship between the number of measurements and the parity checks defining the code.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Computer Science, Information Systems
Daryus Chandra, Soon Xin Ng, Lajos Hanzo
Summary: This study proposes a novel quantum Turbo short-block code design that achieves multiple quantum coding rates. The design uses multiple-rate quantum short-block codes as the outer codes and a quantum unity-rate code as the inner code. Simulation results show that the proposed design performs close to the ultimate limit of the quantum hashing bound.
Article
Education, Scientific Disciplines
Abraham Asfaw, Alexandre Blais, Kenneth R. Brown, Jonathan Candelaria, Christopher Cantwell, Lincoln D. Carr, Joshua Combes, Dripto M. Debroy, John M. Donohue, Sophia E. Economou, Emily Edwards, Michael F. J. Fox, Steven M. Girvin, Alan Ho, Hilary M. Hurst, Zubin Jacob, Blake R. Johnson, Ezekiel Johnston-Halperin, Robert Joynt, Eliot Kapit, Judith Klein-Seetharaman, Martin Laforest, H. J. Lewandowski, Theresa W. Lynn, Corey Rae H. McRae, Celia Merzbacher, Spyridon Michalakis, Prineha Narang, William D. Oliver, Jens Palsberg, David P. Pappas, Michael G. Raymer, David J. Reilly, Mark Saffman, Thomas A. Searles, Jeffrey H. Shapiro, Chandralekha Singh
Summary: The paper provides a roadmap for constructing a quantum engineering education program to meet the workforce needs of the United States and international community. Through a workshop and drawing on best practices, the researchers make specific findings and recommendations, including the design of a first quantum engineering course accessible to all STEM students and the education and training methods for producing quantum-proficient engineers.
IEEE TRANSACTIONS ON EDUCATION
(2022)
Article
Chemistry, Physical
Christian Wellers, Magnus R. Schenkel, Gouri S. Giri, Kenneth R. Brown, Stephan Schiller
Summary: In this study, controlled loading, sympathetic cooling, mass spectrometric identification, and vibrational excitation of ultracold single HD+ ions trapped in a tightly confining radiofrequency trap are demonstrated for the first time using single laser-cooled Be+ ions for sympathetic cooling. The apparatus can also be utilized for preparing other single ions, both lighter and heavier than the coolant ion.
Article
Computer Science, Hardware & Architecture
Prakash Murali, Dripto M. Debroy, Kenneth R. Brown, Margaret Martonosi
Summary: Trapped ions (TIs) are a leading candidate for building Noisy Intermediate-Scale Quantum (NISQ) hardware. A modular architecture named Quantum Charge Coupled Device (QCCD) has been proposed to achieve 50-100 qubit TI devices. Extensive architectural studies have been performed to evaluate the design choices and provide recommendations for highly reliable and performant application executions. The insights from these studies have the potential to influence quantum computing hardware in the near future.
COMMUNICATIONS OF THE ACM
(2022)
Article
Physics, Applied
Bichen Zhang, Swarnadeep Majumder, Pak Hong Leung, Stephen Crain, Ye Wang, Chao Fang, Dripto M. Debroy, Jungsang Kim, Kenneth R. Brown
Summary: In this paper, a method for reducing coherent errors by using hidden inverses is demonstrated. The effectiveness of this method is numerically simulated and experimentally validated on a trapped-ion quantum computer.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Zhubing Jia, Ye Wang, Bichen Zhang, Jacob Whitlow, Chao Fang, Jungsang Kim, Kenneth R. Brown
Summary: The study proposes a general method to determine Fock state distributions and reconstruct the density matrix of arbitrary multimode motional states, applicable to any system with Jaynes-Cummings-type interactions.
PHYSICAL REVIEW LETTERS
(2022)
Letter
Multidisciplinary Sciences
Elis Newham, Pamela G. Gill, Michael J. Benton, Philippa Brewer, Neil J. Gostling, David Haberthuer, Jukka Jernvall, Tuomas Kankanpaa, Aki Kallonen, Charles Navarro, Alexandra Pacureanu, Kelly Richards, Kate Robson Brown, Philipp Schneider, Heikki Suhonen, Paul Tafforeau, Katherine Williams, Berit Zeller-Plumhoff, Ian J. Corfe
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Chao Fang, Ye Wang, Shilin Huang, Kenneth R. Brown, Jungsang Kim
Summary: In quantum computers, crosstalk between the target and neighboring spectator qubits due to the spillover of control signals is a major error source limiting the fidelity of two-qubit entangling gates. This study proposes a crosstalk suppression scheme that eliminates all first-order crosstalk using only local control of the target qubits, as opposed to existing schemes. Experimental results in a laser-driven trapped-ion system show high fidelity for the two-qubit Bell state, indicating the potential applicability of this scheme to other platforms with analogous interaction Hamiltonians.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Applied
Mingyu Kang, Ye Wang, Chao Fang, Bichen Zhang, Omid Khosravani, Jungsang Kim, Kenneth R. Brown
Summary: This study develops filter functions for Molmer-Sorensen gates in trapped-ion quantum computers, accurately predicting the change in gate error due to small parameter fluctuations at any frequency. Experimental results show that using these filter functions can significantly improve gate fidelity in a five-ion chain.
PHYSICAL REVIEW APPLIED
(2023)
Article
Chemistry, Physical
Ke Sun, Chao Fang, Mingyu Kang, Zhendian Zhang, Peng Zhang, David N. N. Beratan, Kenneth R. R. Brown, Jungsang Kim
Summary: This study presents a quantum simulation method to investigate the impact of light polarization on electron transfer between molecules. By controlling the quantum states of trapped atomic ions, we can simulate electron transfer dynamics resembling those in molecules. Using three-level systems instead of traditional two-level systems enhances simulation efficiency and fidelity. We analyze the transfer efficiency by considering the quantum interference of electron coupling pathways and examine potential error sources in the quantum simulations. Trapped-ion systems offer favorable scalability compared to classical computers, enabling richer electron transfer simulations.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Quantum Science & Technology
Mingyu Kang, Wesley C. Campbell, Kenneth R. Brown
Summary: For quantum error-correcting codes, erasures, or errors with known locations, are more favorable than Pauli errors. Convert physical noise into erasures can significantly enhance quantum error correction. In this study, we apply the concept of performing erasure conversion by encoding qubits into metastable atomic states, proposed by Wu, Kolkowitz, Puri, and Thompson in 2022, to trapped ions.
Article
Optics
Lu Qi, Evan C. Reed, Kenneth R. Brown
Summary: Control of the external degree of freedom is crucial for the applications of trapped molecular ions in spectroscopy, precision measurements, and quantum information technology. In this study, we demonstrate near ground-state cooling of axial motional modes of a calcium mono-oxide ion through sympathetic sideband cooling with a cotrapped calcium ion. We also observe that the phonon state of the axial out-of-phase mode of the ion chain remains unchanged while the mode frequency is adiabatically ramped up and/or down, which is essential for investigating the proposed molecular dipole-phonon interaction.
Article
Quantum Science & Technology
Theerapat Tansuwannont, Balint Pato, Kenneth R. Brown
Summary: The Shor fault-tolerant error correction (FTEC) scheme uses transversal gates and ancilla qubits in the cat state to prevent error propagation. An adaptive syndrome measurement technique is introduced to improve the scheme. Simulations show that the proposed protocols can maintain code distance, increase pseudothreshold, and reduce the average number of measurement rounds compared to the traditional Shor scheme.
Article
Optics
Zhubing Jia, Shilin Huang, Mingyu Kang, Ke Sun, Robert F. Spivey, Jungsang Kim, Kenneth R. Brown
Summary: In trapped-ion quantum computers, spin-dependent force and phonons are used to generate two-qubit entangling gates. To maintain high fidelity under fluctuating experimental parameters, robust pulse-design methods are used. An improved method is proposed that guarantees the robustness of the rotation angle against uniform mode-frequency drifts. Experimental results show significantly improved robustness and gate fidelity compared to a single frequency-modulated pulse.
Proceedings Paper
Computer Science, Theory & Methods
Leon Riesebos, Kenneth R. Brown
Summary: Modern quantum computers heavily rely on real-time control systems for operation. However, testing real-time control software is often complex, and existing simulation software is not practical for software testing. To address this issue, we developed an interactive simulator that can simulate signals at the application programming interface level. Our simulation infrastructure achieves an average 6.9 times faster simulation speed compared to hardware execution, with an average accuracy of 97.9% in simulating the position of the timeline cursor when the appropriate configuration is chosen.
2022 IEEE INTERNATIONAL CONFERENCE ON QUANTUM COMPUTING AND ENGINEERING (QCE 2022)
(2022)
Proceedings Paper
Computer Science, Theory & Methods
Leon Riesebos, Brad Bondurant, Jacob Whitlow, Junki Kim, Mark Kuzyk, Tianyi Chen, Samuel Phiri, Ye Wang, Chao Fang, Andrew Van Horn, Jungsang Kim, Kenneth R. Brown
Summary: Real-time control software and hardware are crucial for operating quantum computers. This study proposes a systematic design strategy for modular real-time quantum control software, which can significantly reduce the execution time overhead of kernels without increasing the binary size. The experiment demonstrates the modularity and portability of the software architecture on two different ion-trap quantum systems.
2022 IEEE INTERNATIONAL CONFERENCE ON QUANTUM COMPUTING AND ENGINEERING (QCE 2022)
(2022)