295 citations · 988 across the 25 of their papers we have counts for
27 papers
Error-Corrected QRAM Queries with One-Fault-Tolerant \texttt{CSWAP} Gates
Shifan Xu, Connor T. Hann, Nathan Wiebe +2
Quantum random-access memory (QRAM) enables coherent queries to classical data. However, the \(O(N)\) qubits required for a memory with \(N=2^n\) addresses make QRAM appear vulnera…
Scalable Passive QRAM
Siddhartha Jain, Alexander M. Dalzell, Connor T. Hann
We present a blueprint for implementing the physical QRAM operation in a scalable, passive manner, proving its feasibility in principle. Our construction is passive because for an…
Dissipatively Stabilized 0-n Fock Qubits for Noise-Biased Quantum Computing
Su Direkci, Simon Lieu, Kyungjoo Noh +1
Noise-biased qubits have bit-flip errors that are exponentially suppressed relative to phase-flip errors, and offer a promising route toward fault-tolerant quantum computing. Howev…
Bias-preserving cat-cat CNOT gate via vacuum-conditional beam-splitter
Yufeng Ye, Connor T. Hann, Kyungjoo Noh +4
Cat qubits can exhibit strong noise bias due to their exponentially enhanced bit-flip times and only polynomially reduced phase-flip times with increasing photon number, which make…
Readout-induced degradation of transmon lifetimes: interplay of TLSs and qubit spectral reshaping
Ziwen Huang, Jimmy Shih-Chun Hung, Mouktik Raha +9
Measurement backaction degrades dispersive readout of superconducting qubits even at modest drive strengths, often via the reduction of qubit lifetimes during readout. In this work…
Cavity-mediated cross-cross-resonance gate
Alexey V. Gorshkov, Daniel Cohen, Arbel Haim +8
We propose a cavity-mediated gate between two transmon qubits or other nonlinear superconducting elements. The gate is realized by driving both qubits at a frequency that is near-r…
A distillation-teleportation protocol for fault-tolerant QRAM
Alexander M. Dalzell, András Gilyén, Connor T. Hann +5
We present a protocol for fault-tolerantly implementing the logical quantum random access memory (QRAM) operation, given access to a specialized, noisy QRAM device. For coherently…
Frequency-noise-insensitive universal control of Kerr-cat qubits
Lennart Maximilian Seifert, Connor T. Hann, Kyungjoo Noh
We theoretically study the influence of frequency uncertainties on the operation of a Kerr-cat qubit. As the mean photon number increases, Kerr-cat qubits provide an increasing lev…
Viewing protected superconducting qubits through the lens of the cat qubit
Simon Lieu, Emma L. Rosenfeld, Kyungjoo Noh +1
We draw analogies between protected superconducting qubits and bosonic qubits by studying the fluxonium Hamiltonian in its Fock basis. The mean-field phase diagram of fluxonium (at…
Hybrid cat-transmon architecture for scalable, hardware-efficient quantum error correction
Connor T. Hann, Kyungjoo Noh, Harald Putterman +6
Dissipative cat qubits are a promising physical platform for quantum computing, since their large noise bias can enable more hardware-efficient quantum error correction. In this wo…
Preserving phase coherence and linearity in cat qubits with exponential bit-flip suppression
Harald Putterman, Kyungjoo Noh, Rishi N. Patel +17
Cat qubits, a type of bosonic qubit encoded in a harmonic oscillator, can exhibit an exponential noise bias against bit-flip errors with increasing mean photon number. Here, we foc…
Hardware-efficient quantum error correction via concatenated bosonic qubits
Harald Putterman, Kyungjoo Noh, Connor T. Hann +118
In order to solve problems of practical importance, quantum computers will likely need to incorporate quantum error correction, where a logical qubit is redundantly encoded in many…
Cross-resonance control of an oscillator with an auxiliary fluxonium qubit
Guo Zheng, Simon Lieu, Emma L. Rosenfeld +2
The conditional displacement (CD) gate between an oscillator and a discrete-variable auxiliary qubit plays a key role in quantum information processing tasks, such as enabling univ…
Designing high-fidelity two-qubit gates between fluxonium qubits
Emma L. Rosenfeld, Connor T. Hann, David I. Schuster +2
We take a bottom-up, first-principles approach to design a two-qubit gate between fluxonium qubits for minimal error, speed, and control simplicity. Our proposed architecture consi…
Quantum algorithms: A survey of applications and end-to-end complexities
Alexander M. Dalzell, Sam McArdle, Mario Berta +10
The anticipated applications of quantum computers span across science and industry, ranging from quantum chemistry and many-body physics to optimization, finance, and machine learn…
Systems Architecture for Quantum Random Access Memory
Shifan Xu, Connor T. Hann, Ben Foxman +2
Operating on the principles of quantum mechanics, quantum algorithms hold the promise for solving problems that are beyond the reach of the best-available classical algorithms. An…
Error Suppression for Arbitrary-Size Black Box Quantum Operations
Gideon Lee, Connor T. Hann, Shruti Puri +2
Efficient suppression of errors without full error correction is crucial for applications with NISQ devices. Error mitigation allows us to suppress errors in extracting expectation…
Data centers with quantum random access memory and quantum networks
Junyu Liu, Connor T. Hann, Liang Jiang
In this paper, we propose the Quantum Data Center (QDC), an architecture combining Quantum Random Access Memory (QRAM) and quantum networks. We give a precise definition of QDC, an…
Resilience of quantum random access memory to generic noise
Connor T. Hann, Gideon Lee, S. M. Girvin +1
Quantum random access memory (QRAM)--memory which stores classical data but allows queries to be performed in superposition--is required for the implementation of numerous quantum…
Building a fault-tolerant quantum computer using concatenated cat codes
Christopher Chamberland, Kyungjoo Noh, Patricio Arrangoiz-Arriola +13
We present a comprehensive architectural analysis for a proposed fault-tolerant quantum computer based on cat codes concatenated with outer quantum error-correcting codes. For the…
Single-shot number-resolved detection of microwave photons with error mitigation
Jacob C. Curtis, Connor T. Hann, Salvatore S. Elder +4
Single-photon detectors are ubiquitous and integral components of photonic quantum cryptography, communication, and computation. Many applications, however, require not only detect…
High-fidelity measurement of qubits encoded in multilevel superconducting circuits
Salvatore S. Elder, Christopher S. Wang, Philip Reinhold +7
Qubit measurements are central to quantum information processing. In the field of superconducting qubits, standard readout techniques are not only limited by the signal-to-noise ra…
Hardware-efficient quantum random access memory with hybrid quantum acoustic systems
Connor T. Hann, Chang-Ling Zou, Yaxing Zhang +4
Hybrid quantum systems in which acoustic resonators couple to superconducting qubits are promising quantum information platforms. High quality factors and small mode volumes make a…
Robust readout of bosonic qubits in the dispersive coupling regime
Connor T. Hann, Salvatore S. Elder, Christopher S. Wang +3
High-fidelity qubit measurements play a crucial role in quantum computation, communication, and metrology. In recent experiments, it has been shown that readout fidelity may be imp…