papers

Publications (14)

quant-ph2022

Robust preparation of Wigner-negative states with optimized SNAP-displacement sequences

Marina Kudra, Mikael Kervinen, Ingrid Strandberg +13

Hosting non-classical states of light in three-dimensional microwave cavities has emerged as a promising paradigm for continuous-variable quantum information processing. Here we ex…

quant-ph2023

Multipartite entanglement in a microwave frequency comb

Shan W. Jolin, Gustav Andersson, J. C. Rivera Hernández +6

Significant progress has been made with multipartite entanglement of discrete qubits, but continuous variable systems may provide a more scalable path toward entanglement of large…

quant-ph2022

Simple, reliable and noise-resilient continuous-variable quantum state tomography with convex optimization

Ingrid Strandberg

Precise reconstruction of unknown quantum states from measurement data, a process commonly called quantum state tomography, is a crucial component in the development of quantum inf…

quant-ph2022

PennyLane: Automatic differentiation of hybrid quantum-classical computations

Ville Bergholm, Josh Izaac, Maria Schuld +65

PennyLane is a Python 3 software framework for differentiable programming of quantum computers. The library provides a unified architecture for near-term quantum computing devices,…

quant-ph2018

Steady-state generation of Wigner negative states in 1D resonance fluorescence

Fernando Quijandría, Ingrid Strandberg, Göran Johansson

In this work we demonstrate numerically that the nonlinearity provided by a continuously driven two-level system (TLS) allows for the generation of Wigner-negative states of the el…

quant-ph2021

Propagating Wigner-Negative States Generated from the Steady-State Emission of a Superconducting Qubit

Yong Lu, Ingrid Strandberg, Fernando Quijandría +3

We experimentally demonstrate the steady-state generation of propagating Wigner-negative states from a continuously driven superconducting qubit. We reconstruct the Wigner function…

quant-ph2025

Deterministic generation of frequency-bin-encoded microwave photons

Jiaying Yang, Maryam Khanahmadi, Ingrid Strandberg +7

A distributed quantum computing network requires a quantum communication channel between spatially separated processing units. In superconducting circuits, such a channel can be im…

quant-ph2019

Numerical study of Wigner negativity in one-dimensional steady-state resonance fluorescence

Ingrid Strandberg, Yong Lu, Fernando Quijandría +1

In a numerical study, we investigate the steady-state generation of nonclassical states of light from a coherently driven two-level atom in a one-dimensional waveguide. Specificall…

quant-ph2023

Deterministic generation of shaped single microwave photons using a parametrically driven coupler

Jiaying Yang, Axel Eriksson, Mohammed Ali Aamir +5

A distributed quantum computing system requires a quantum communication channel between spatially separated processing units. In superconducting circuits, such a channel can be rea…

quant-ph2021

Wigner negativity in the steady-state output of a Kerr parametric oscillator

Ingrid Strandberg, Göran Johansson, Fernando Quijandría

The output field from a continuously driven linear parametric oscillator may exhibit considerably more squeezing than the intracavity field. Inspired by this fact, we explore the n…

quant-ph2025

Entanglement of photonic modes from a continuously driven two-level system

Jiaying Yang, Ingrid Strandberg, Alejandro Vivas-Viana +7

The ability to generate entangled states of light is a key primitive for quantum communication and distributed quantum computation. Continuously driven sources, including those bas…

quant-ph2023

Digital homodyne and heterodyne detection for stationary bosonic modes

Ingrid Strandberg, Axel Eriksson, Baptiste Royer +2

Homo- and heterodyne detection are fundamental techniques for measuring propagating electromagnetic fields. However, applying these techniques to stationary fields confined in cavi…

quant-ph2025

Overhead in Quantum Circuits with Time-Multiplexed Qubit Control

Marvin Richter, Ingrid Strandberg, Simone Gasparinetti +1

When scaling up quantum processors in a cryogenic environment, it is desirable to limit the number of qubit drive lines going into the cryostat, since fewer lines makes cooling of…

quant-ph2025

Dynamical excitation control and multimode emission of an atom-photon bound state

Claudia Castillo-Moreno, Kazi Rafsanjani Amin, Ingrid Strandberg +3

Atom-photon bound states arise from the coupling of quantum emitters to the band edge of dispersion-engineered waveguides. Thanks to their tunable-range interactions, they are prom…