Coexistence of nonequilibrium density and equilibrium energy distribution of quasiparticles in a superconducting qubit

T Connolly, PD Kurilovich, S Diamond, H Nho… - Physical Review Letters, 2024‏ - APS
The density of quasiparticles typically observed in superconducting qubits exceeds the
value expected in equilibrium by many orders of magnitude. Can this out-of-equilibrium …

Dynamically enhancing qubit-photon interactions with antisqueezing

M Villiers, WC Smith, A Petrescu, A Borgognoni… - PRX Quantum, 2024‏ - APS
The interaction strength of an oscillator to a qubit grows with the oscillator's vacuum field
fluctuations. The well-known degenerate parametric oscillator has revived interest in the …

Low-pass filter with ultrawide stopband for quantum computing applications

R Rehammar, S Gasparinetti - IEEE Transactions on Microwave …, 2023‏ - ieeexplore.ieee.org
A new type of low-pass filter based on a leaky coaxial waveguide is presented. The filter has
minimal insertion loss in the passband, while at the same time, high attenuation in the …

Scalable cryoelectronics for superconducting qubit control and readout

M Ahmad, C Giagkoulovits, S Danilin… - Advanced Intelligent …, 2022‏ - Wiley Online Library
Quantum computing promises an exponentially higher computational power than classical
computers; although all the building blocks have become available, certain constraints still …

[HTML][HTML] Impedance-matched coplanar-waveguide metal-powder low-pass filters for cryogenic applications

M Lyatti, R Roth, I Gundareva, D Grützmacher… - Review of Scientific …, 2024‏ - pubs.aip.org
We developed impedance-matched metal-powder low-pass filters based on coplanar
waveguide design and characterized them at room temperature and 77.4 K. The coplanar …

Heralded and robust W-state generation for distant superconducting qubits with practical microwave pulse scattering

Z Guo, Z **e, Y Wang, Z Li, T Li - Applied Physics Letters, 2023‏ - pubs.aip.org
Nonlocal multipartite entanglement holds significant potential for both fundamental physics
and practical applications. We present a robust protocol for generating remote …

[HTML][HTML] Absorptive filters for quantum circuits: Efficient fabrication and cryogenic power handling

A Paquette, J Griesmar, G Lavoie, R Albert… - Applied Physics …, 2022‏ - pubs.aip.org
We present an efficient fabrication method for absorptive microwave filters based on
Eccosorb CR-124. Filters are fabricated from readily available parts, and their cutoff …

Robust cryogenic matched low-pass coaxial filters for quantum computing applications

AI Ivanov, VI Polozov, VV Echeistov… - Applied Physics …, 2023‏ - pubs.aip.org
Electromagnetic noise is one of the main external factors decreasing superconducting qubit
coherence. Matched coaxial filters can prevent microwave and IR photons' negative …

Automated error correction in superdense coding, with implementation on superconducting quantum computer

K Nilesh, P Joshi, P Panigrahi - arxiv preprint arxiv:2210.15161, 2022‏ - arxiv.org
Construction of a fault-tolerant quantum computer remains a challenging problem due to
unavoidable noise in quantum states and the fragility of quantum entanglement. However …

The Fe micropowder low-pass coaxial filter tunable by magnetic field

A Dumik, O Kalenyuk, S Futimsky… - 2022 IEEE 2nd …, 2022‏ - ieeexplore.ieee.org
In this paper, the behavior of the coaxial filter filled with carbonyl iron micropowder was
studied. Amplitude-frequency characteristics (AFC) and phase-frequency characteristics …