A5007336265- Diamond and Carbon-based Materials Research
- Quantum and electron transport phenomena
- Semiconductor materials and devices
- Atomic and Subatomic Physics Research
- Quantum optics and atomic interactions
- Silicon Carbide Semiconductor Technologies
- Force Microscopy Techniques and Applications
- Electronic and Structural Properties of Oxides
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Electron Spin Resonance Studies
- Advanced Fiber Laser Technologies
- Advanced NMR Techniques and Applications
- Silicon and Solar Cell Technologies
- Ion-surface interactions and analysis
- Quantum Computing Algorithms and Architecture
- High-pressure geophysics and materials
- Integrated Circuits and Semiconductor Failure Analysis
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Neural Networks and Applications
- Luminescence Properties of Advanced Materials
- Molecular Junctions and Nanostructures
- Machine Learning in Materials Science
- ECG Monitoring and Analysis
Argonne National Laboratory
2019-2024
University of Chicago
2016-2022
University of Hong Kong
2022
Tohoku University
2018
Advanced Institute of Materials Science
2018
London Centre for Nanotechnology
2012-2017
University College London
2012-2017
University of Oxford
2012-2016
University of Illinois Chicago
2016
SignificanceAtomic defects in solid-state materials are promising candidates as quantum bits, or qubits. New actively being investigated hosts for new defect qubits; however, there no unifying guidelines that can quantitatively predict qubit performance a material. One of the most critical property qubits is their coherence. While cluster correlation expansion (CCE) techniques useful to simulate coherence electron spins defects, they computationally expensive investigate broad classes stable...
Observation of single vanadium telecom emitters with spin registers provides a promising platform for quantum communication.
Spin defects in silicon carbide have the advantage of exceptional electron spin coherence combined with a near-infrared spin-photon interface, all material amenable to modern semiconductor fabrication. Leveraging these advantages, we integrated highly coherent single neutral divacancy spins commercially available p-i-n structures and fabricated diodes modulate local electrical environment defects. These devices enable deterministic charge-state control broad Stark-shift tuning exceeding 850...
Decoherence limits the physical realization of qubits, and its mitigation is critical for development quantum science technology. We construct a robust qubit embedded in decoherence-protected subspace, obtained by applying microwave dressing to clock transition ground-state electron spin silicon carbide divacancy defect. The universally protected from magnetic, electric, temperature fluctuations, which account nearly all relevant decoherence channels solid state. This culminates an increase...
Interfacing between various elements of a computer--from memory to processors long range communication--will be as critical for quantum computers it is classical today. Paramagnetic rare-earth doped crystals, such Nd(3+):Y2SiO5(YSO), are excellent candidates interface: they known exhibit optical coherence lifetimes (for communication via photons), possess nuclear spin (memory), and have in addition an electron that can offer hybrid coupling with superconducting qubits (processing). Here we...
Defects in silicon carbide (SiC) have emerged as a favorable platform for optically-active spin-based quantum technologies. Spin qubits exist specific charge states of these defects, where the ability to control can provide enhanced spin-dependent readout and long-term stability qubits. We investigate this state two major spin 4H-SiC, divacancy (VV) vacancy (Vsi), obtaining bidirectional optical conversion between bright dark defects. measure increased photoluminescence from VV ensembles by...
Abstract Transition metal ions provide a rich set of optically active defect spins in wide bandgap semiconductors. Chromium (Cr 4+ ) silicon-carbide (SiC) produces spin-1 ground state with narrow, spectrally isolated, spin-selective, near-telecom optical interface. However, previous studies were hindered by material quality resulting limited coherent control. In this work, we implant Cr into commercial 4H-SiC and show optimal activation after annealing above 1600 °C. We measure an ensemble...
Optically-active point defects in various host materials, such as diamond and silicon carbide (SiC), have shown significant promise local sensors of magnetic fields, electric strain temperature. Current sensing techniques take advantage the relaxation coherence times spin state within these defects. Here we show that defect charge can also be used to sense environment, particular high frequency (MHz-GHz) complementing established spin-based techniques. This is enabled by optical conversion...
Interfacing solid-state defect electron spins to other quantum systems is an ongoing challenge. The ground-state spin's weak coupling its environment not only bestows excellent coherence properties but also limits desired drive fields. excited-state orbitals of these electrons, however, can exhibit stronger phononic and electric Here, we demonstrate electrically driven coherent interference in the optical transition single, basally oriented divacancies commercially available 4H silicon...
Rare-earth ions (REIs) have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s 5p orbitals, making them good candidates for solid-state quantum memory. The emission of Er3+ telecom C-band (1530 nm–1565 nm) makes it especially attractive this application. In order build practical, scalable devices, REI needs be embedded a non-interacting host material, preferably one that can integrated with silicon. paper, we show isovalently...
Central spin decoherence caused by nuclear baths is often a critical issue in various quantum computing schemes, and it has also been used for sensing single-nuclear spins. Recent theoretical studies suggest that central can act as probe of many-body physics baths; however, identification detection correlations spins nanoscale systems are highly challenging. Here, taking phosphorus donor electron 29Si bath our model system, we discover both theoretically experimentally produce identifiable...
We present a complete theoretical treatment of Stark effects in bulk doped silicon, whose predictions are supported by experimental measurements. A multivalley effective mass theory, dealing nonperturbatively with valley-orbit interactions induced donor-dependent central cell potential, allows us to obtain very reliable picture the donor wave function within relatively simple framework. Variational optimization $1s$ binding energies calculated new trial function, pseudopotential two fitting...
Electric fields can be used to tune donor spins in silicon using the Stark shift, whereby electron wave function is displaced by an electric field, modifying hyperfine coupling between spin and nuclear spin. We present a technique based on dynamic decoupling of accurately determine illustrate this antimony donors isotopically purified silicon-28. then demonstrate two different methods use dc field combined with applied resonant radio-frequency (rf) conditionally control spins. The first...
The decoherence of mixed electron-nuclear spin qubits is a topic great current importance, but understanding still lacking: While important mechanisms for arise from quantum bath environments with slow decay correlations, the only analytical framework explaining observed sharp variations times magnetic field based on suppression classical noise. Here we obtain general expression central system which exposes significant differences between quantum-bath and by We perform measurements bismuth...
Commercially impactful quantum algorithms such as chemistry and Shor's algorithm require a number of qubits gates far beyond the capacity any existing processor. Distributed architectures, which scale horizontally by networking modules, provide route to commercial utility will eventually surpass capability single computing module. Such processors consume remote entanglement distributed between modules realize logic. Networked computers therefore rapidly distribute high fidelity modules. Here...
Bismuth (${}^{209}$Bi) is the deepest group V donor in silicon and possesses most extreme characteristics such as a 9/2 nuclear spin 1.5 GHz hyperfine coupling. These lead to several potential advantages for Si:Bi electron qubit compared more common phosphorus donor. Most previous studies on have been performed using natural where linewidths coherence times are limited by presence of ${}^{29}$Si impurities. Here, we describe resonance (ESR) double (ENDOR) ${}^{209}$Bi isotopically pure...
A fundamental question for understanding the decoherence of quantum spin qubits interacting with a bath spins in environment is nature noise affecting qubit - can it be modeled as classical or are effects important? Here authors experimentally demonstrate that favorable case bismuth electron donors silicon near values magnetic field known clock transitions, nuclear approximated Gaussian noise. This finding expected to influence efforts optimize control based computation.
Abstract The performance of a room temperature, zero-field MASER operating at 1.45 GHz has been examined. Nanosecond laser pulses, which are essentially instantaneous on the timescale spin dynamics, allow visible-to-microwave conversion efficiency and temporal response to be measured as function excitation energy. It is observed that timing amplitude output pulse correlated with energy: higher energy, microwave pulses have larger appear after shorter delay than those recorded lower Seeding...
Control of local lattice perturbations near optically-active defects in semiconductors is a key step to harnessing the potential solid-state qubits for quantum information science and nanoscale sensing. We report development stroboscopic scanning X-ray diffraction microscopy approach real-space imaging dynamic strain used correlation with microscopic photoluminescence measurements. demonstrate this technique 4H-SiC, which hosts long-lifetime room temperature vacancy spin defects. Using...
Nuclear spin registers in the vicinity of electron spins solid state systems offer a powerful resource to address challenge scalability quantum architectures. We investigate here properties 29Si nuclear surrounding donor atoms silicon, and consider use such spins, combined with spin, as register coupled spin. find coherence nearby is effectively protected by presence leading times second timescale—over two orders magnitude greater than bulk silicon. theoretically for error correction (QEC),...
Rare-earth ion doped oxide thin films integrated on silicon substrates provide a route toward scalable, chip-scale platforms for quantum coherent devices. Erbium-doped TiO2 is an attractive candidate: the Er3+ optical transition compatible with C-band fiber communications, while insulating dielectric process technology. Through structural and studies of Er-doped grown via molecular beam deposition silicon, SrTiO3, sapphire substrates, we have explored impact polycrystallinity microstructure...