72 citations · 245 across the 21 of their papers we have counts for
21 papers
Adaptive Spectroscopy of Fast Two-Level-System Dynamics in Superconducting Qubits
Fabrizio Berritta, David Pahl, Lukas Pahl +15
Parasitic two-level-system (TLS) defects are a major source of energy relaxation and temporal instability in superconducting quantum processors. Our sub-second adaptive spectroscop…
Frequency-resolved decoherence spectroscopy of a semiconductor charge qubit coupled to a high-impedance resonator
Ekaterina Al-Tavil, Wonjin Jang, David J. van Woerkom +10
Superconducting resonators coupled to semiconductor quantum dots provide a powerful platform to investigate light-matter interaction and decoherence mechanisms in solid-state quant…
Evidence of Quantum Machine Learning Advantage with Tens of Noisy Qubits
Onur Danaci, Yash J. Patel, Riccardo Molteni +3
Learning problems involving quantum data are natural candidates for demonstrating an advantage in quantum machine learning. Recent results indicate that, for certain tasks and unde…
Operating a bistable qubit
Fabrizio Berritta, Jan A. Krzywda, Tom Dvir +4
Parasitic two-level-system (TLS) defects limit the stability and performance of solid-state quantum processors. Their interaction with a qubit can cause discrete, stochastic shifts…
Coherence Protection for Mobile Spin Qubits in Silicon
Jan A. Krzywda, Yuta Matsumoto, Maxim De Smet +6
Mobile spin qubit architectures promise flexible connectivity for efficient quantum error correction and relaxed device layout constraints, but their viability rests on preserving…
Statistical Structure of Charge Disorder in Si/SiGe Quantum Dots
Saeed Samadi, Łukasz Cywiński, Jan A. Krzywda
Properties of quantum dot based spin qubits have significant inter-device variability due to unavoidable presence of various types of disorder in semiconductor nanostructures. A si…
Real-time adaptive tracking of fluctuating relaxation rates in superconducting qubits
Fabrizio Berritta, Jacob Benestad, Jan A. Krzywda +17
The fidelity of operations on a solid-state quantum processor is fundamentally bounded by environmental decoherence. Characterizing environmental fluctuations is challenging becaus…
Efficient Qubit Calibration by Binary-Search Hamiltonian Tracking
Fabrizio Berritta, Jacob Benestad, Lukas Pahl +14
We present and experimentally implement a real-time protocol for calibrating the frequency of a resonantly driven qubit, achieving exponential scaling in calibration precision with…
Decoherence of electron spin qubit during transfer between two semiconductor quantum dots at low magnetic fields
Jan A. Krzywda, Łukasz Cywiński
Electron shuttling is one of the current avenues being pursued to scale semiconductor quantum dot-based spin qubits. Adiabatic spin qubit transfer along a chain of tunnel-coupled q…
Physics-informed tracking of qubit fluctuations
Fabrizio Berritta, Jan A. Krzywda, Jacob Benestad +9
Environmental fluctuations degrade the performance of solid-state qubits but can in principle be mitigated by real-time Hamiltonian estimation down to time scales set by the estima…
QDarts: A Quantum Dot Array Transition Simulator for finding charge transitions in the presence of finite tunnel couplings, non-constant charging energies and sensor dots
Jan A. Krzywda, Weikun Liu, Evert van Nieuwenburg +1
We present QDarts, an efficient simulator for realistic charge stability diagrams of quantum dot array (QDA) devices in equilibrium states. It allows for pinpointing the location o…
Efficient adaptive Bayesian estimation of a slowly fluctuating Overhauser field gradient
Jacob Benestad, Jan A. Krzywda, Evert van Nieuwenburg +1
Slow fluctuations of Overhauser fields are an important source for decoherence in spin qubits hosted in III-V semiconductor quantum dots. Focusing on the effect of the field gradie…
Real-time two-axis control of a spin qubit
Fabrizio Berritta, Torbjørn Rasmussen, Jan A. Krzywda +9
Optimal control of qubits requires the ability to adapt continuously to their ever-changing environment. We demonstrate a real-time control protocol for a two-electron singlet-trip…
Correlations of spin splitting and orbital fluctuations due to 1/f charge noise in the Si/SiGe Quantum Dot
Marcin Kępa, Łukasz Cywiński, Jan A. Krzywda
Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochast…
Blueprint of a scalable spin qubit shuttle device for coherent mid-range qubit transfer in disordered Si/SiGe/SiO
Veit Langrock, Jan A. Krzywda, Niels Focke +3
Silicon spin qubits stand out due to their very long coherence times, compatibility with industrial fabrication, and prospect to integrate classical control electronics. To achieve…
Interplay of charge noise and coupling to phonons in adiabatic electron transfer between quantum dots
Jan A. Krzywda, Łukasz Cywiński
Long-distance transfer of quantum information in architectures based on quantum dot spin qubits will be necessary for their scalability. One way of achieving it is to simply move t…
Adiabatic electron charge transfer between two quantum dots in presence of 1/f noise
Jan Krzywda, Łukasz Cywiński
Controlled adiabatic transfer of a single electron through a chain of quantum dots has been recently achieved in GaAs and Si/SiGe based quantum dots, opening prospects for turning…
The dynamical-decoupling-based spatiotemporal noise spectroscopy
Jan Krzywda, Piotr Szańkowski, Łukasz Cywiński
Here we demonstrate how the standard, temporal-only, dynamical-decoupling-based noise spectroscopy method can be extended to also encompass the spatial degree of freedom. This spat…
Decoherence-assisted detection of entanglement of two qubit states
Jan Krzywda, Piotr Szańkowski, Jan Chwedeńczuk +1
We show that the decoherence, which in the long run destroys quantum features of a system, can be used to reveal the entanglement in a two-qubit system. To this end, we consider a…
Localization of a magnetic moment using a two-qubit probe
Jan Krzywda, Łukasz Cywiński, Piotr Szańkowski
A nanomagnet precessing in an external magnetic field can be treated as a source of narrow-bandwidth magnetic noise, that leaves characteristic fingerprints in decoherence of a nea…
Phonon-mediated generation of quantum correlations between quantum dot qubits
Jan Krzywda, Katarzyna Roszak
We study the generation of quantum correlations between two excitonic quantum dot qubits due to their interaction with the same phonon environment. Such generation results from the…