S. Bogdanov

University of Illinois, Urbana-Champaign | UIUC · Department of Electrical and Computer Engineering

Dielectric passivation of long wavelength infrared type-II InAs/GaSb superlattice photodetectors with different active region doping profiles has been studied. SiO ₂ passivation was shown to be efficient as long as it was not put in direct contact with the highly doped superlattice. A hybrid graded doping profile combined with the shallo...

We present a hybrid photodetector design that inherits the advantages of traditional photoconductive and photovoltaic devices. The structure consists of a barrier layer blocking the transport of majority holes in a p-type semiconductor, resulting in an electrical transport due to minority carriers with low current density. By using the M-structure...

Type II superlattices (T2SLs), a system of interacting multiquantum wells, were introduced by Nobel Laureate L. Esaki in the 1970s. Since then, this material system has drawn a lot of attention, especially for infrared detection and imaging. In recent years, the T2SL material system has experienced incredible improvements in material growth quality...

One of the main characteristics of optical imaging systems is spatial resolution, which is restricted by the diffraction limit to approximately half the wavelength of the incident light. Along with the recently developed classical super-resolution techniques, which aim at breaking the diffraction limit in classical systems, there is a class of quan...

Transduction of quantum signals between the microwave and the optical ranges will unlock powerful hybrid quantum systems enabling information processing with superconducting qubits and low-noise quantum networking through optical photons. Most microwave-to-optical quantum transducers suffer from thermal noise due to pump absorption. We analyze the...

Diamond color centers have been widely studied in the field of quantum optics. The negatively charged silicon vacancy (SiV−) center exhibits a narrow emission linewidth at the wavelength of 738 nm, a high Debye–Waller factor, and unique spin properties, making it a promising emitter for quantum information technologies, biological imaging, and sens...

We report the first demonstration of single silicon vacancy center creation in 20 nm nanodiamonds using silicon ion implantation combined with thermal annealing. Room-temperature single photon emission with linewidth below 10 nm is observed.

Optically active color centers in nanodiamonds offer unique opportunities for generating and manipulating quantum states of light. These mechanically, chemically, and optically robust emitters can be produced in mass quantities, deterministically manipulated, and integrated with a variety of quantum device geometries and photonic material platforms...

Optically active color centers in nanodiamonds offer unique opportunities for generating and manipulating quantum states of light. These mechanically, chemically, and optically robust emitters can be produced in mass quantities, deterministically manipulated, and integrated with a variety of quantum device geometries and photonic material platforms...

Hybrid systems coupling quantum spin defects (QSD) and magnons can enable unique spintronic device functionalities and probes for magnetism. Here, we add electric field control of magnon-QSD coupling to such systems by integrating ferromagnet-ferroelectric composite multiferroic with nitrogen-vacancy (NV) center spins. Combining quantum relaxometry...

We investigate the impact of various fluctuation mechanisms on the time-averaged resistance and noise performance in superconducting devices based on epitaxial titanium nitride (TiN) films. We show that a very large noise at the resistive transition originates from spontaneous resistance (R) fluctuations. These fluctuations are characterized by a L...

We investigate the temporal and spatial scales of resistance fluctuations (R-fluctuations) at the superconducting resistive transition in thin epitaxial TiN films, accessed through voltage fluctuations measurements in current-biased samples. The measured Lorentzian spectrum of the R-fluctuations identifies their correlation time, which is shown to...

One of the main characteristics of optical imaging systems is the spatial resolution, which is restricted by the diffraction limit to approximately half the wavelength of the incident light. Along with the recently developed classical super-resolution techniques, which aim at breaking the diffraction limit in classical systems, there is a class of...

Accurate sizing of individual nanoparticles is crucial for the understanding of their physical and chemical properties and for their use in nanoscale devices. Optical sizing methods are non-invasive, rapid, and versatile. However, the low optical response of weakly absorbing subwavelength dielectric nanoparticles poses a fundamental challenge for t...

A machine learning assisted framework significantly speeds up image acquisition in super-resolution microscopy based on photon antibunching. The technique is compatible with a CW excitation regime and applicable to a wide range of quantum emitters.

The nanoscale magnetic field of magnons has emerged as a promising resource for coherently driving qubits such as quantum spin defects (QSD) and developing versatile probes for magnetism and other types of quantum matter. Tuning this coupling via electric field would provide a path to address the outstanding challenges of enhancing QSD-based sensin...

Simeon I. Bogdanov, Vladimir M. Shalaev and coworkers propose and realize a single‐photon source based on a solid‐state quantum emitter in a nanoparticle encapsulated between two metallic layers (article number 2000889). The devices feature single‐photon emission times of a few picoseconds and preferentially emit in‐plane rather than out‐of‐plane p...

Deterministic nanoassembly may enable unique integrated on‐chip quantum photonic devices. Such integration requires a careful large‐scale selection of nanoscale building blocks such as solid‐state single‐photon emitters by means of optical characterization. Second‐order autocorrelation is a cornerstone measurement that is particularly time‐consumin...

Integrated on‐demand single‐photon sources are critical for the implementation of photonic quantum information processing systems. To enable practical quantum photonic devices, the emission rates of solid‐state quantum emitters need to be substantially enhanced and the emitted signal must be directly coupled to an on‐chip circuitry. The photon emis...

On-chip scalable integration represents a major challenge for practical quantum devices. One particular challenge is to implement on-chip optical readout of spins in diamond. This readout requires simultaneous application of optical and microwave fields along with the efficient collection of fluorescence. These requirements are typically met using...

Quantum emitters coupled to plasmonic nanostructures can act as exceptionally bright sources of single photons, operating at room temperature. Plasmonic mode volumes supported by these nanostructures can be several orders of magnitude smaller than the cubic wavelength, which leads to dramatically enhanced light–matter interactions and drastically i...

Single quantum emitters offer useful functionalities for quantum optics, but measurements of their properties are time-consuming. We demonstrate that machine learning dramatically reduces data collection time (1s), increasing the accuracy of second-order autocorrelation measurements (>90%).

We demonstrate a quantum plasmonic launcher - a metal-based chip-compatible nanostructure featuring near-THz emission rates. Nanodiamonds with single NV centers are sandwiched between two silver films coupling about half of the emission into in-plane surface plasmons.

We analytically establish the fundamental limit for quantum emission enhancement in plasmonic nanostructures combining smaller (cavity) and larger (antenna) modes. We confirm this result numerically and optimize the performance of nanoantennas experimentally through controlled photomodification.

We establish the fundamental limit for quantum emission enhancement in plasmonic nanostructures combining smaller (cavity) and larger (antenna) modes. We confirm this result numerically and optimize the performance of nanoantennas through controlled photomodification.

The characterization of single quantum emitters is a time-consuming process. We have demonstrated that machine learning methods can dramatically reduce data collection time(<1s), and increase measurement accuracy of second-order fluorescence autocorrelation(>90%).

We analyze the evolution of the normal and superconducting properties of epitaxial TiN films, characterized by high Ioffe-Regel parameter values, as a function of the film thickness. As the film thickness decreases, we observe an increase of the residual resistivity, that becomes dominated by diffusive surface scattering for d≤20nm. At the same tim...

Integrated on-demand single-photon sources are critical for the implementation of photonic quantum information processing systems. To enable practical quantum photonic devices, the emission rates of solid-state quantum emitters need to be substantially enhanced and the emitted signal must be directly coupled to an on-chip circuitry. The photon emis...

Rapid and deterministic nanoscale assembly of quantum emitters remains to be a daunting challenge for the realization of practical, on-chip quantum photonic devices. The major bottleneck is the time-consuming second-order photon autocorrelation measurements for the classification of solid-state quantum emitters into "single" and "non-single" photon...

On-chip scalable integration represents a major challenge for practical quantum devices. One particular challenge is to implement on-chip optical readout of spins in diamond. This readout requires simultaneous application of optical and microwave fields along with an efficient collection of fluorescence. The readout is typically accomplished via bu...

The use of nanoscale plasmonic metamaterials can optimize photon-matter interactions

We analyze the evolution of the normal and superconducting electronic properties in epitaxial TiN films as a function of the film thickness with high Ioffe-Regel parameter values. As the film thickness decreases, we observe an increase of in the residual resistivity, which becomes dominated by diffusive surface scattering for d<20nm. At the same ti...

Quantum emitters coupled to plasmonic nanoantennas produce single photons at unprecedentedly high rates in ambient conditions. This enhancement of quantum emitters' radiation rate is based on the existence of optical modes with highly sub-diffraction volumes supported by plasmonic gap nanoantennas. Nanoantennas with gap sizes on the order of few na...

We demonstrate a technique for highly controllable assembly of single-photon sources coupled to plasmonic nanoantennas with optimal emitter positioning on the nanoscale, resulting in fluorescence decay rates beyond 10 GHz in single nitrogen-vacancy centers.

We transfer a pre-characterized nanodiamond with a single nitrogen-vacancy (NV) center onto an epitaxial silver substrate and deterministically couple it to a nanopatch antenna. The NV retains its coherent spin dynamics in this process.

Solid-state quantum emitters are in high demand for emerging technologies such as advanced sensing and quantum information processing. Generally, these emitters are not sufficiently bright for practical applications, and a promising solution consists in coupling them to plasmonic nanostructures. Plasmonic nanostructures support broadband modes, mak...

We propose highly efficient hybrid plasmonic bullseye antennas for collecting photon emission from nm-sized quantum emitters. In our approach, the emitter radiation is coupled to surface plasmon polaritons that are consequently converted into highly directional out-of-plane emission. The proposed configuration consists of a high-index titania bulls...

We report unprecedentedly bright fluorescence from single nitrogen-vacancy centers in nanodiamonds. The intensity enhancement is achieved by placing nanodiamonds in gaps between a metal film and randomly dispersed metal nanoparticles. The shortening of fluorescence lifetime below 1 ns combined with an efficient outcoupling of plasmons into the far-...

Ultrafast emission rates obtained from quantum emitters coupled to plasmonic nanoantennas have recently opened fundamentally new possibilities in quantum information and sensing applications. Plasmonic nanoantennas greatly improve the brightness of quantum emitters by dramatically shortening their fluorescence lifetimes. Gap plasmonic nanocavities...

Hyperbolic metamaterials are anisotropic media that behave as metals or as dielectrics depending on light polarization. These plasmonic materials constitute a versatile platform for promoting both spontaneous and stimulated emission for a broad range of emitter wavelengths. We analyze experimental realizations of a single–photon source and of a pla...

Solid-state quantum emitters are prime candidates for the realization of fast, on-demand single-photon sources. The improvement in photon emission rate and collection efficiency for point-like emitters can be achieved by using a near-field coupling to nanophotonic structures. Plasmonic metamaterials with hyperbolic dispersion have previously been d...

Nitrogen-vacancy centers in diamond allow for coherent spin state manipulation at room temperature, which could bring dramatic advances to nanoscale sensing and quantum information technology. We introduce a novel method for the optical measurement of the spin contrast in dense nitrogen-vacancy (NV) ensembles. This method brings a new insight into...

A novel method for measuring the spin contrast in large nitrogen-vacancy ensembles in diamond is introduced. We use this method to study how the photonic density of states must be engineered in order to minimize the uncertainty of spin readout for nanoscale sensing applications.

On-chip integration of quantum optical systems could be a major factor enabling photonic quantum technologies. Unlike the case of electronics, where the essential device is a transistor and the dominant material is silicon, the toolbox of elementary devices required for both classical and quantum photonic integrated circuits is vast. Therefore, man...

We will review the list of alternative plasmonic materials and provide a focused discussion on transition metal nitrides for refractory plasmonics. Nanostructures made of alternative plasmonic materials and their performance will be presented. Article not available.

Efficient generation of single photons is essential for the development of photonic quantum technologies. We have demonstrated that coupling a nanodiamond nitrogen-vacancy (NV) center to CMOS-compatible nanophotonic structures results in significant reduction of the excited state lifetime, increase in the collected single–photon emission, and modif...

Diamond based nitrogen-vacancy (NV) centers are promising solid state defects for applications in quantum information technologies. On the one hand, there is a growing interest in enhancing their single-photon emission by coupling them to plasmonic structures. On the other hand, the dependence of emission intensity on the electron spin state enable...

Scientists are looking for new, breakthrough solutions that can greatly advance computing and networking systems. These solutions will involve quantum properties of matter and light as promised by the ongoing experimental and theoretical work in the areas of quantum computation and communication. Quantum photonics is destined to play a central role...

Pour fabriquer de nouveaux dispositifs, en particulier des composants optoélectroniques, les laboratoires font appel à des nouveaux matériaux qu’ils constituent atome par atome grâce aux techniques issues des nanosciences.

Y2O3 was applied to passivate a long-wavelength infrared type-II superlattice gated photodetector array with 50% cut-off wavelength at 11 μm, resulting in a saturated gate bias that was 3 times lower than in a SiO2 passivated array. Besides effectively suppressing surface leakage, gating technique exhibited its ability to enhance the quantum effici...

Capacitance-voltage measurement was utilized to characterize impurities in the non-intentionally doped region of Type-II InAs/GaSb superlattice p-i-n photodiodes. Ionized carrier concentration versus temperature dependence revealed the presence of a kind of defects with activation energy below 6 meV and a total concentration of low 1015 cm−3. Corre...

By using gating technique, surface leakage generated by SiO2 passivation in long-wavelength infrared type-II superlattice photodetector is suppressed, and different surface leakage mechanisms are disclosed. By reducing the SiO2 passivation layer thickness, the saturated gated bias is reduced to −4.5 V. At 77 K, dark current densities of gated devic...