Publications by Vladimir Manucharyan

Verifying the analogy between transversely coupled spin-1/2 systems and inductively-coupled fluxoniums

We report a detailed characterization of two inductively coupled superconducting fluxonium qubits for implementing high-fidelity cross-resonance gates. Our circuit stands out because it behaves very closely to the case of two transversely coupled spin- 1 / ...

2025

Photon-instanton scattering in a superconducting circuit: Beyond the very high impedance regime

Vladimir Manucharyan

American Physical Society (APS)2025

24 Days-Stable CNOT Gate on Fluxonium Qubits with over 99.9% Fidelity

Vladimir Manucharyan

Fluxonium qubit is a promising elementary building block for quantum information processing due to its long coherence time combined with a strong anharmonicity. In this paper, we realize a 60-ns direct cnot gate on two inductively coupled fluxoniums, which ...

2025

Fluxonium qubits in a flip-chip package

Vladimir Manucharyan

The strong anharmonicity and high coherence times inherent to fluxonium superconducting circuits are beneficial for quantum information processing. In addition to requiring high-quality physical qubits, a quantum processor needs to be assembled in a manner ...

American Physical Society (APS)2024

Millisecond Coherence in a Superconducting Qubit

Vladimir Manucharyan

Improving control over physical qubits is a crucial component of quantum computing research. Here we report a superconducting fluxonium qubit with uncorrected coherence time T-2* = 1.48 +/- 0.13 ms, exceeding the state of the art for transmons by an order ...

2023

Tuning the inductance of Josephson junction arrays without SQUIDs

Vladimir Manucharyan

It is customary to use arrays of superconducting quantum interference devices (SQUIDs) for implementing magnetic field-tunable inductors. Here, we demonstrate an equivalent tunability in a (SQUID-free) array of single Al/AlOx/Al Josephson tunnel junctions. ...

2023

Metrics and properties of optimal gauges in multimode cavity QED

Vladimir Manucharyan

Multimode cavity quantum electrodynamics describes, for example, the coupling between an atom and a multimode electromagnetic resonator. The gauge choice is important for practical calculations in truncated Hilbert spaces, because the exact gauge invarianc ...

2023

Voltage-activated parametric entangling gates based on gatemon qubits

Vladimir Manucharyan

We describe the generation of entangling gates on superconductor-semiconductor hybrid qubits by ac voltage modulation of the Josephson energy. Our numerical simulations demonstrate that the unitary error can be below 10(-5) in a variety of 75-ns-long two-q ...

American Physical Society (APS)2023