Publications (16)
Exponential speedups in fault-tolerant processing of quantum experiments
Ishaan Kannan, Harald Putterman, Jordan Cotler
Quantum information processing has the potential to substantially enhance how we learn from physical experiments, but coupling a quantum processor to an experimental sample introdu…
When quantum thermal states look classical
Harald Putterman, Alexander Zlokapa, Jordan Cotler
The paper analyzes how quantum Gibbs states retain classical properties such as lack of entanglement and magic at finite temperatures, establishing a hierarchy of classical‑to‑quan…
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…
Bias-preserving cat-cat CNOT gate via vacuum-conditional beam-splitter
Yufeng Ye, Yufeng, Ye +6
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…
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…
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…
Quantum Approximate Optimization of Non-Planar Graph Problems on a Planar Superconducting Processor
Matthew P. Harrigan, Kevin J. Sung, Matthew Neeley +83
We demonstrate the application of the Google Sycamore superconducting qubit quantum processor to combinatorial optimization problems with the quantum approximate optimization algor…
Stabilizing a Bosonic Qubit using Colored Dissipation
Harald Putterman, Joseph Iverson, Qian Xu +4
Protected qubits such as the 0- qubit, and bosonic qubits including cat qubits and GKP qubits offer advantages for fault-tolerance. Some of these protected qubits (e.g., 0-…
Creating and manipulating a Laughlin-type fractional quantum Hall state on a quantum computer with linear depth circuits
Armin Rahmani, Kevin J. Sung, Harald Putterman +3
Here we present an efficient quantum algorithm to generate an equivalent many-body state to Laughlin's fractional quantum Hall state on a digitized quantum computer. Our a…
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…
Phonon engineering of atomic-scale defects in superconducting quantum circuits
Mo Chen, John Clai Owens, Harald Putterman +2
Noise within solid-state systems at low temperatures, where many of the degrees of freedom of the host material are frozen out, can typically be traced back to material defects tha…
Hartree-Fock on a superconducting qubit quantum computer
Frank Arute, Kunal Arya, Ryan Babbush +79
As the search continues for useful applications of noisy intermediate scale quantum devices, variational simulations of fermionic systems remain one of the most promising direction…
Observation of separated dynamics of charge and spin in the Fermi-Hubbard model
Frank Arute, Kunal Arya, Ryan Babbush +96
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these systems on quantum computers may avo…
Restrictions on non-Clifford fault tolerance and ruling out beyond-SQL quantum metrology
Constantin Cedillo Vayson de Pradenne, Ishaan Kannan, Harald Putterman +1
The paper proves limits on transversal non‑Clifford gates in stabilizer codes, showing these constraints prevent fault‑tolerant transversal sensing that would surpass the standard…
Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons
Harry Levine, Arbel Haim, Jimmy S. C. Hung +110
Quantum error correction with erasure qubits promises significant advantages over standard error correction due to favorable thresholds for erasure errors. To realize this advantag…
Exponential suppression of bit or phase flip errors with repetitive error correction
Zijun Chen, Kevin J. Satzinger, Juan Atalaya +88
Realizing the potential of quantum computing will require achieving sufficiently low logical error rates. Many applications call for error rates in the regime, but state…