A5043645906- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Quantum-Dot Cellular Automata
- Atomic and Subatomic Physics Research
- Electronic and Structural Properties of Oxides
- Physics of Superconductivity and Magnetism
- Advanced Data Storage Technologies
- Diverse academic and cultural studies
- Cryptographic Implementations and Security
- Security and Verification in Computing
- Agricultural Economics and Policy
- Management, Economics, and Public Policy
- Quantum Mechanics and Applications
- Radiation Effects in Electronics
Delft University of Technology
2019-2021
QuTech
2019-2021
Conditional-phase (cz) gates in transmons can be realized by flux pulsing computational states towards resonance with noncomputational ones. We present a 40 ns cz gate based on bipolar pulse suppressing leakage (0.1%) interference and approaching the speed limit set exchange coupling. This harnesses built-in echo to enhance fidelity (99.1%) is robust long-timescale distortion flux-control line, ensuring repeatability. Numerical simulations matching experiment show that limited high-frequency...
We introduce the sudden variant (SNZ) of Net Zero scheme realizing controlled-$Z$ (CZ) gates by baseband flux control transmon frequency. SNZ CZ operate at speed limit transverse coupling between computational and non-computational states maximizing intermediate leakage. The key advantage is tuneup simplicity, owing to regular structure conditional phase leakage as a function two parameters. realize in multi-transmon processor, achieving $99.93\pm0.24\%$ fidelity $0.10\pm0.02\%$ compatible...
Abstract Quantum computing is poised to solve practically useful problems which are computationally intractable for classical supercomputers. However, the current generation of quantum computers limited by errors that may only partially be mitigated developing higher-quality qubits. error correction (QEC) will thus necessary ensure fault tolerance. QEC protects logical information cyclically measuring syndrome about errors. An essential part decoder, uses compute likely effect on degrees...
Abstract We introduce spectral quantum tomography, a simple method to extract the eigenvalues of noisy few-qubit gate, represented by trace-preserving superoperator, in SPAM-resistant fashion, using low resources terms gate sequence length. The provide detailed information, supplementary known gate-quality measures such as fidelity, and can be used diagnostic tool. apply our one- two-qubit gates on two different superconducting systems available cloud, namely QuTech Quantum Infinity IBM...
Leakage outside of the qubit computational subspace poses a threatening challenge to quantum error correction (QEC). We propose scheme using two leakage-reduction units (LRUs) that mitigate these issues for transmon-based surface code, without requiring an overhead in terms hardware or QEC-cycle time as previous proposals. For data qubits, we consider microwave drive transfer leakage readout resonator, where it quickly decays, ensuring this negligibly disturbs states realistic system...
Leakage outside of the qubit computational subspace, present in many leading experimental platforms, constitutes a threatening error for quantum correction (QEC) qubits. We develop leakage-detection scheme via Hidden Markov models (HMMs) transmon-based implementations surface code. By performing realistic density-matrix simulations distance-3 code (Surface-17), we observe that leakage is sharply projected and leads to an increase surface-code defect probability neighboring stabilizers....
Abstract Future fault-tolerant quantum computers will require storing and processing data in logical qubits. We realize a suite of operations on distance-two qubit stabilized using repeated error detection cycles. Logical include initialization into arbitrary states, measurement the cardinal bases Bloch sphere, universal set single-qubit gates. For each type operation, we observe higher performance for variants over non-fault-tolerant variants, quantify difference through detailed...
Quantum computing is poised to solve practically useful problems which are computationally intractable for classical supercomputers. However, the current generation of quantum computers limited by errors that may only partially be mitigated developing higher-quality qubits. error correction (QEC) will thus necessary ensure fault tolerance. QEC protects logical information cyclically measuring syndrome about errors. An essential part decoder, uses compute likely effect on degrees freedom and...
Scaling up the number of qubits and speeding execution quantum algorithms are important steps towards reaching advantage. This poses heavy demands particularly on control stack, as pulses need to be distributed an increasing channels variational require rapid interleaving classical computation. Assessing bottlenecks in stack is therefore key making it ready for However, existing benchmark suites suffer from lack detail due indirect access hardware. In this work, we present Q-Profile, a tool...