A5016657206- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Photonic and Optical Devices
- Semiconductor Quantum Structures and Devices
- Physics of Superconductivity and Magnetism
- Advanced Fluorescence Microscopy Techniques
- Terahertz technology and applications
- Quantum-Dot Cellular Automata
- Advancements in Semiconductor Devices and Circuit Design
- Spectroscopy and Laser Applications
- Advanced Fiber Laser Technologies
- Advanced Optical Sensing Technologies
- Mechanical and Optical Resonators
- Photoacoustic and Ultrasonic Imaging
- Atomic and Subatomic Physics Research
- Neural Networks and Reservoir Computing
- Quantum optics and atomic interactions
- Semiconductor materials and devices
- Biofield Effects and Biophysics
- Cell Image Analysis Techniques
- Advanced Measurement and Metrology Techniques
- Advanced Biosensing Techniques and Applications
- Electromagnetic Compatibility and Noise Suppression
Delft University of Technology
2013-2023
QuTech
2015-2023
Kavli Energy NanoScience Institute
2019
Microwave spectroscopy experiments have been performed on two quantum levels of a macroscopic superconducting loop with three Josephson junctions. Level repulsion the ground state and first excited is found where classical persistent-current states opposite polarity are degenerate, indicating symmetric antisymmetric superpositions states. The persistent currents 0.5 microampere correspond to center-of-mass motion millions Cooper pairs.
The distribution of entangled states across the nodes a future quantum internet will unlock fundamentally new technologies. Here we report on experimental realization three-node entanglement-based network. We combine remote based diamond communication qubits into scalable phase-stabilized architecture, supplemented with robust memory qubit and local logic. In addition, achieve real-time feed-forward gate operations capitalize novel capabilities this network to realize two canonical protocols...
Realizing robust quantum information transfer between long-lived qubit registers is a key challenge for science and technology. Here we demonstrate unconditional teleportation of arbitrary states diamond spin qubits separated by 3 meters. We prepare the teleporter through photon-mediated heralded entanglement two distant electron spins subsequently encode source in single nuclear spin. By realizing fully deterministic Bell-state measurement combined with real-time feed-forward achieve each...
Quasiparticle excitations adversely affect the performance of superconducting devices in a wide range applications. They limit sensitivity photon detectors astronomy, accuracy current sources metrology, cooling power micro-refrigerators, and could break topological protection Majorana qubits. In circuits for quantum information processing, tunneling quasiparticles across Josephson junctions constitutes decoherence mechanism. As relaxation pure dephasing times transmon-type charge qubits now...
We have built a relatively simple, highly efficient, THz emission and detection system centered around 15 fs Ti:sapphire laser. In the system, 200 mW of laser power is focused to 120 μm diam spot between two silverpaint electrodes on surface semi-insulating GaAs crystal, kept at temperature near 300 K, biased with 50 kHz, ±400 V square wave. Using rapid delay scanning lock-in we obtain probe quantum-noise limited signals using standard electro-optic scheme 1-mm-thick (110) oriented ZnTe...
Many theoretical studies predict that DNA sequencing should be feasible by monitoring the transverse current through a graphene nanoribbon while molecule translocates nanopore in ribbon. Such readout would benefit from special transport properties of graphene, provide ultimate spatial resolution because single-atom layer thickness and facilitate high-bandwidth measurements. Previous experimental attempts to measure such inplane signals were however dominated trivial capacitive response....
We investigate the magnetic field and temperature dependence of single-electron spin lifetime in silicon quantum dots find a 2.8 ms at 1.1 K. develop model based on spin-valley mixing that Johnson noise two-phonon processes limit relaxation low high respectively. also effect charge linear up to 4 These results contribute understanding are promising for qubit operation elevated temperatures.
A quantum computer comprises both qubits and their classical electronic interface. While much research is currently devoted solely to qubits, an efficient controller also urgently needed for a scalable computer. This study uses analytical techniques expose the effect of nonideal circuit blocks in on qubit fidelity, all required operations, how fidelity affected by limited performance general-purpose, room-temperature equipment typically used with few types available today. Tailor-made...
Abstract The recently reported violation of a Bell inequality using entangled electronic spins in diamonds (Hensen et al ., Nature 526, 682–686) provided the first loophole-free evidence against local-realist theories nature. Here we report on data from second experiment same experimental setup with minor modifications. We find CHSH-Bell 2.35 ± 0.18, agreement run, yielding an overall value S = 2.38 0.14. calculate resulting P -values and combined tests. provide additional analysis...
We demonstrate the active suppression of transmon qubit dephasing induced by dispersive measurement, using parametric amplification and analog feedback. By real-time processing homodyne record, feedback controller reverts stochastic quantum phase kick imparted measurement on qubit. The operation matches a model trajectories with efficiency η˜≈0.5, consistent result obtained postselection. overcome bandwidth limitations chain numerically optimizing signal in loop provide theoretical...
Superconducting electronic devices have re-emerged as contenders for both classical and quantum computing due to their fast operation speeds, low dissipation long coherence times. An ultimate demonstration of is lasing. We use one the fundamental aspects superconductivity, ac Josephson effect, demonstrate a laser made from junction strongly coupled multi-mode superconducting cavity. A dc voltage bias provides source microwave photons, while circuit's nonlinearity allows efficient...
A widely-used quantum programming paradigm comprises of both the data How and control How. Existing hardware cannot well support How, significantly limiting range software executable on hardware. By analyzing constraints in microarchitecture, we found that existing assembly languages are either too high-level or restricted to comprehensive Also, as observed with microinstruction set QuMIS [1], instruction architecture (QISA) design may suffer from limited scalability Hexibility because...
Quantum computers promise to solve certain problems that are intractable for classical computers, such as factoring large numbers and simulating quantum systems. To date, research in computer engineering has focused primarily at opposite ends of the required system stack: devising high-level programming languages compilers describe optimize algorithms, building reliable low-level hardware. Relatively little attention been given using compiler output fully control operations on experimental...
Entanglement-based quantum networks will provide exciting opportunities for science and engineering. Here, we report the realization of a three-node network by generating distributed multi-partite entangled states performing entanglement swapping through an intermediary node.
We observe individual tunnel events of a single electron between quantum dot and reservoir, using nearby point contact (QPC) as charge meter. The QPC is capacitively coupled to the dot, conductance changes by about 1% if number electrons on one. voltage biased current monitored with an IV-convertor at room temperature. can resolve separated only 8 $\mu$s, limited noise from IV-convertor. Shot in sets 25 ns lower bound accessible timescales.
We present a new readout method for superconducting flux qubit, based on the measurement of Josephson inductance quantum interference device that is inductively coupled to qubit. The intrinsic detection efficiency and backaction are suitable fast nondestructive determination state as needed multiple qubits in computer. performed spectroscopy qubit we measured relaxation times order $80\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$.
We present two pulse schemes for actively depleting measurement photons from a readout resonator in the nonlinear dispersive regime of circuit QED. One method uses digital feedback conditioned on outcome while other is unconditional. In absence analytic forms and symmetries to exploit this regime, depletion pulses are numerically optimized using Powell method. shorten photon time by more than six inverse linewidths compared passive waiting. quantify benefit emulating an ancilla qubit...
We present an overview of pulsed THz emission and detection schemes give results a highly efficient, water-cooled, semi-large aperture emitter. Using electro-optic we obtain dynamic range more than 5000 in total measurement time 20 ms, which represents the highest for emitters centred around femtosecond laser oscillators to date. find that sensitivity is completely determined by photon shot-noise probe beam. As application our efficient emitter, first phonon resonance apertureless scanning...
NMi Van Swinden Laboratory, Thijsseweg 11, 2629 JA Delft, The Netherlands We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as tool for distance measurement in an interferometric scheme. A proof of principle this method, proposed by Ye [5], is provided measuring displacement about 15 cm air and comparing it to reference value from calibrated laser interferometer. experiment shows the new scheme easily achieves accuracy better than one optical fringe.
In state-of-the-art quantum processors, the time spent tuning gates is a significant portion of experimental run time, and could continue to grow, as number qubits achievable fidelities both rise. The authors devise tune-up protocol that realizes tenfold speed-up over traditional methods, by constructing cost function using real-time correlations outcomes nondemolition measurements. This method can be readily generalized other problems, including two-qubit measurement operations,...