Nitrogen doped 4H-SiC epitaxial layers were investigated by deep level transient spectroscopy after irradiation with 6 MeV electrons. The influence of C/Si ratio, N doping level, and growth rate on the behavior of the prominent Z_1,2 and EH_6,7 levels during... (Read more)

The wide-band-gap zinc oxide-based diluted magnetic semiconductors currently attract considerable attention due to their possible use in spintronic devices. In this work, we studied ZnO nanowire samples synthesized on 10×10 mm² a-plane sapphire substrates by high-pressure... (Read more)

We present the results of an electron paramagnetic resonance study of homogeneous single phase Zn_1−xMn_xO thin films with Mn concentrations varying between x=0.07 and x=0.34. Our results show antiferromagnetic (AF) coupling in the entire... (Read more)

Electron spin resonance measurements on 4 and 40 nm thick (HfO₂)_0.6(SiO₂)_0.4 and (HfO₂)_0.4(SiO₂)_0.6 high-κ films on (100)Si wafers detected P_b0 and P_b1... (Read more)

The effect of HF etching of the silicon oxide shell covering the surface of Si nanocrystals (NCs) on the subsequent room-temperature atmospheric oxidation of Si-NCs has been investigated by means of photoluminescence measurements, Fourier transform infrared spectroscopy, and electron paramagnetic... (Read more)

Electron spin resonance (ESR) results of Gd³⁺ in YbAl₃ and LuAl₃ are analyzed using a multiband (f-, d-, and p-type) model of correlated conduction electrons. The need for a multiband analysis of our results is based on the following... (Read more)

Conduction band electrons in colloidal ZnO quantum dots have been prepared photochemically and examined by electron paramagnetic resonance spectroscopy. Nanocrystals of 4.6 nm diameter containing single S-shell conduction band electrons have g^*=1.962 and a room-temperature... (Read more)

We describe how the spin coherence time of a localized electron spin in solids, i.e., a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the spectral diffusion of the electron spin resonance frequency... (Read more)

Electron spin resonance analysis of (100)Si/LaAlO₃ structures reveals the absence of a Si/SiO₂-type interface in terms of archetypal Si-dangling bond-type Si/SiO₂ interface defects (P_b0,P_b1). With no... (Read more)

Low pressure chemical vapor deposition of Si₃N₄ on oxidized Si (111) surfaces causes a change in the properties of the dominant interface defect, the P_b center, observed by electron paramagnetic resonance. The change in the signature of the... (Read more)

The effect of forming gas and vacuum annealing on the concentration of carbon dangling bond (P_bC) centers at 3C- and 4H-SiC/SiO₂ interfaces has been studied by electron paramagnetic resonance (EPR) spectroscopy. Our results show efficient passivation at 400 °C and... (Read more)

Hydrogen-vacancy related defect (H1) in chemical vapor deposition homoepitaxial diamond films has been investigated by electron paramagnetic resonance and cathodoluminescence. It is found that the concentration of H1 significantly decreases as the dilution... (Read more)

We present a detailed study of the electron magnetic resonance (EMR) properties of Ni nanoparticles (NPs) placed in the bundles of single-walled carbon nanotubes produced by arc discharge with Ni catalyst. The behavior of EMR signals has been investigated in the 10–300 K temperature range for... (Read more)

The influence of Hf-based dielectrics on the underlying SiO₂ interfacial layer (IL) in high-k gate stacks is investigated. An increase in the IL dielectric constant, which correlates to an increase of the positive fixed charge density in the IL, is found to depend on the starting,... (Read more)

Hydrogenated amorphous silicon carbide (a-SiC:H) films have been deposited using magnetron sputtering technique. An integrated investigation of the effect of vacuum annealing temperature on photoluminescence properties and paramagnetic defects and its correlation with structural... (Read more)

The efficacy of diffusing cobalt into window-grade polycrystalline ZnSe during high-temperature anneals has been studied. Absorption, photoluminescence (PL), time-resolved PL, and electron paramagnetic resonance (EPR) were used to characterize samples with cobalt concentrations ranging from... (Read more)

ZnO–Sb2O3–B2O3 glasses containing different concentrations of MnO ranging from 0 to 1.0 mol% were prepared. A number of studies, viz. optical absorption, infrared and ESR spectra and magnetic susceptibility, were carried out as a function of manganese ion concentration. The analysis of... (Read more)

We report on metal-organic chemical vapour deposition growth of GaN:Fe and its characterization by means of high-resolution X-ray diffraction, secondary ion mass spectroscopy, electron spin resonance, and magnetization measurements. Electron spin resonance studies demonstrate the existence of Fe in... (Read more)

The annealing behavior of defects observed in electron paramagnetic resonance (EPR) and photoluminescence (PL) is discussed. We consider the divacancy (the P6/P7 EPR centers) and a previously unreported EPR center that we suggest is a V_C-V_Si-V_C... (Read more)

Electron paramagnetic resonance (EPR) spectroscopy of rare earth ions in crystals is a powerful tool to analyze the hyperfine structure of the rare earth ground state. This can be useful for coherent spectroscopy and quantum information applications where the hyperfine structure of the electronic... (Read more)

We have irradiated Li₂NH powder with MeV electrons at room temperature and investigated the introduced defects with electron spin resonance. Conduction electron spin resonance indicates the presence of nanosize metallic Li colloids seen as a Lorentzian line with a g=2.0023 and a... (Read more)

This work provides a consistent picture of the structural, optical, and electronic properties of Fe-doped GaN. A set of high-quality GaN crystals doped with Fe at concentrations ranging from 5×10¹⁷ cm^–3 to 2×10²⁰ cm^–3 is... (Read more)

We report on room-temperature coherent manipulation of the spin of a single nitrogen-vacancy center in diamond and a study of its coherence as a function of magnetic field. We use magnetic resonance to induce Rabi nutations and apply a Hahn spin echo to remove the effect of low-frequency dephasing.... (Read more)

ESR spectroscopy is an important tool in polarized solid target material research, since it allows us to study the paramagnetic centers, which are used for the dynamic nuclear polarization (DNP). The polarization behavior of the different target materials is strongly affected by the properties of... (Read more)

Contradictory results concerning the formation of a ferromagnetic state in Mn doped ZnO layers have been reported in the last years. We present the results of an electron paramagnetic resonance study on homogeneous single phase n-type conductive Zn_1–xMn_xO... (Read more)

The absorption and magnetic circular dichroism (MCD) spectra of Zn_1–xCr_xTe for x=0.0625, 0.25, and 1.0 are studied using the first-principles method. The calculated MCD spectra are found to be well consistent with the experimental measurement at the... (Read more)

Structural aspects of clustering of rare earth ions in oxide glasses have been studied for the last several years in relation to their applications in photonics. However, the mechanism of homogenization of the spatial distribution of rare earth ions by codoping, typically with Al or P, is still not... (Read more)

Three dominant iron centers are studied in the as-grown ⁵⁷Fe-doped single KTaO₃ crystals. For each of the centers, which were labeled as rhombic Fe_Ta³⁺ and two axial Fe-related centers Fe_K³⁺-O_I and (Fe). The... (Read more)

The differences between variously doped and grown samples of manganese-doped GaAs have been studied and set in relation to the magnetic and electronic properties of these materials. For interion exchange and contrary to the resolved hyperfine and crystal field contributions from the ionized acceptor... (Read more)

By utilizing multifrequency electron paramagnetic resonance (EPR) spectroscopy, the iron functional center in Fe³⁺-modified polycrystalline lead zirconate (PbZrO₃) was studied. The single phase polycrystalline sample remained orthorhombic and antiferroelectric down to 20 K as... (Read more)

The effects of isochronal thermal treatments on three -irradiation-induced point defects, named the E, ODC(II), and H(I) centers, are investigated in various types of commercial silica (a-SiO₂). ODC(II) is investigated by means of photoluminescence spectroscopy,... (Read more)

Continuous-wave (cw) electron paramagnetic resonance (EPR) at both X-band and W-band frequencies, pulsed-EPR, and pulsed electron nuclear double resonance (ENDOR) were used to study phosphorus shallow donors in 3C-, 4H-, and 6H-SiC doped with phosphorus (P) during... (Read more)

An electron spin resonance (ESR) method is applied to a pentacene field-effect device to investigate gate-induced hole carriers in such devices. Clear field-induced ESR signals are observed, demonstrating that all of the field-injected carriers have S=1/2 spins. Anisotropic ESR signals due to... (Read more)

We report Stark shift measurements for ¹²¹Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on a Sb-implanted ²⁸Si epilayer are used to apply the electric fields. Two quadratic Stark effects are resolved: a decrease of the... (Read more)

In the case of colossal magnetoresistance in the perovskite manganites, "double exchange" mediated by the itinerant spins is believed to play a key role in the ferromagnetism. In contrast, the conventional "Heisenberg" interaction, i.e., direct (unmediated) interaction between... (Read more)

We report a study by electron paramagnetic resonance on the E_α point defect in amorphous silicon dioxide (a-SiO₂). Our experiments were performed on γ-ray irradiated oxygen-deficient materials and pointed out that the ²⁹Si... (Read more)

Electron paramagnetic resonance and ab initio supercell calculations suggest that the P6/P7 centers, which were previously assigned to the photoexcited triplet states of the carbon vacancy-antisite pairs in the double positive charge state, are related to the triplet ground... (Read more)

We report on the magnetic properties of thoroughly characterized Zn_1-xCo_xO epitaxial thin films, with low Co concentration, x=0.003–0.005. Magnetic and EPR measurements, combined with crystal field theory, reveal that isolated Co²⁺ ions in... (Read more)

The EPR spectra of Fe3+ in high-quality thick freestanding hydride vapor phase grown GaN have been studied in the X- and Q-band. A complex resonance pattern with numerous lines of different intensities provided by three different defects is observed for these nearly stress-free iron-doped samples.... (Read more)

Phosphorus shallow donors having the symmetry lower than Td are studied by pulsed EPR. In diamond:P and 3C–SiC:P, the symmetry is lowered to D2d and the density of the donor wave function on the phosphorus atom exhibits a predominant p-character. In 4H–SiC:P with the site symmetry of... (Read more)

Electron spin resonance (ESR) and electron-nuclear double resonance experiments were performed in the 2D electron systems of GaAs/AlxGa1−xAs quantum well and heterojunction samples in the vicinity of the unity filling factor in the regime of the quantum Hall effect. As is well known, the ESR... (Read more)

ZnO substrate crystals from two different sources, and epitaxial layers have been studied by SEM, AFM, photoluminescence and EPR. Although fabricated by the same growth principle, i.e. the hydrothermal technique, the substrates differ in terms of purity and structural quality. In the PL spectra of... (Read more)

Zn2SiO4:Mn2+ is one of the green light luminants used for cathode ray tubes of televisions. Recently, optical materials emitting strong visible light under lower energy excitation have been expected. To obtain new luminants of high quality, we prepared Mn ion doped ZnO–GeO2 glasses and glass... (Read more)

ESR measurements of Zn-codoped GaAs:Er,O have been performed at 9.49 GHz. Several anisotropic ESR signals (A, B, and C) are observed. We found that the intensity of the C center decreases together with the decrease of the PL intensity by increasing the doping amount of Zn, while the changes of the... (Read more)

Zinc oxide crystals grown by the seeded chemical vapor transport method have been annealed in zinc vapor at 1100 °C for 30 min. These thermochemical reduction treatments produce a deep red coloration in the crystals and increase their n-type electrical conductivity. Electron paramagnetic... (Read more)

The Ti³⁺ center, based on a regular Ti site perturbed by an oxygen vacancy (V_O), is identified by electron spin resonance (ESR) in textured BaTiO₃ films. The center shows tetragonal symmetry along cubic 100 axes with g-factors: g=1.997,... (Read more)

Polycrystalline Zn1 − xMnxO was synthesized by co-precipitation method with xvarying between 0.01 and 0.10. Although X-ray diffraction patterns show a typical würtzite structure with no additional peaks for all samples, Raman spectroscopy indicates the appearance of an additional mode in... (Read more)

Electron spin resonance (ESR) measurements of Zn-codoped GaAs:Er,O grown by organometallic vapor phase epitaxy have been performed at 9.49 GHz. Several anisotropic ESR signals (named as A, B, and C) are observed. The angular and temperature dependences of the A, B, and C signals are quite... (Read more)

ZnMnO nanoclusters were synthesized by the sol–gel method. The structural and magnetic characters were investigated. The XRD spectrum shows ZnMnO nanoclusters are hexagonal wurtzite structures and a small quantity of ZnMn2O4 phase is also present in the spectrum. The percentages of Zn and Mn... (Read more)

Differential scanning calorimetric studies, spectroscopic studies (viz., optical absorption, ESR, infrared spectra) and thermoluminescence studies of ZnF2–MO–TeO2 (MO=ZnO, CdO and PbO) glasses doped with different concentrations of chromium ions have been investigated. Results have... (Read more)

The structural, optical and magnetic properties of nanostructured ZnO films co-doped with cobalt and aluminium have been studied. The nanocrystalline films, with cluster sizes in range 50–100 nm, were deposited by pulsed laser ablation in a mixed atmosphere of oxygen and helium. The... (Read more)

Interface defects related to negative-bias temperature instability (NBTI) in an ultrathin plasma-nitrided SiON/ Si<100> system were characterized by using conductance–frequency measurements, electron-spin resonance measure- ments, and synchrotron radiation X-ray photoelectron spectroscopy. It was confirmed that NBTI is reduced by using D₂-annealing instead of the usual H₂-annealing. Interfacial Si dangling bonds (P_b1 and P_b0 centers) were detected in a sample subjected to negative-bias temperature stress (NBTS). Although we suggest that NBTS also generates non-Pb defects, it does not seem to generate nitrogen dangling bonds. These results show that NBTI of the plasma-nitrided SiON/Si system is predominantly due to P_b depassivation. Plasma nitridation was also found to increase the P_b1/P_b0 density ratio, modify the P_b1 defect structure, and increase the latent interface trap density by generating Si suboxides at the interface. These changes are likely to be the causes of NBTI in ultrathin plasma-nitrided SiON/Si systems. (Read more)

Ab initio total-energy calculations are presented for intrinsic defects in GaAs with a particular emphasis on hyperfine interactions in order to clarify the atomic structure of the various As_Ga-related defects. For the As_Ga-X₂ defect complex the... (Read more)

The Ky1, Ky2, and Ky3 centers are the dominant defects produced in the electron-irradiated p-type 6H-SiC crystals. The electron paramagnetic resonance study of these defects has been performed in the temperature range of 4.2–300 K at... (Read more)

Electron spin resonance (ESR) was used to study neutron-induced defects in silicon as functions of anneal temperature T_an. For T_an below 200 °C, the ESR response is dominated by the Si-P3 and Si-P6 spectra, as observed before. At T_an=200 ... (Read more)

The exchange coupling of Fe centers in GaAs crystals is studied by electron spin resonance (ESR). Transitions to a superparamagnetic state and to an impurity ferromagnetism domain are analyzed. A study of a system of single-domain magnetically ordered regions in GaAs:Fe with the transition to a ferromagnetic state occurring at the temperature T _C1 = 460 K is described. It is shown that impurity ferromagnetism with a transition temperature T _C2 of 60 K in a disordered system of Fe centers randomly distributed among superparamagnetic regions exists in GaAs:Fe. (Read more)

Electron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO–PbO–B2O3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of spin-Hamiltonian parameters... (Read more)

Diluted magnetic semiconductors (DMS), systems formed by replacing cations of the host semiconductor material with transition-metal ions, are developed for further use in spintronics. A good combination as a DMS is Zn1−xMnxO due to the ZnO wide band gap (3.37 eV) and the matching ionic... (Read more)

We prepared ZnO nanostructures using chemical and thermal evaporation methods. The properties of the fabricated nanostructures were studied using scanning electron microscopy, x-ray diffraction, photoluminescence, and electron paramagnetic resonance (EPR) spectroscopy. It was found that the... (Read more)

The properties of ZnO tetrapod and multipod structures were investigated using scanning electron microscopy, x-ray diffraction, photoluminescence (PL), and electron paramagnetic resonance (EPR) spectroscopy. While there is relationship between g = 1.96 EPR and green PL in some of the samples,... (Read more)

Electron spin resonance (ESR) measurements of GaAs:Er,O grown by organometallic vapor phase epitaxy have been performed at 9.49 GHz from 4.5 to 13 K. Several anisotropic ESR signals (A, B, C, and D) are observed, which is consistent with the previous reports. We... (Read more)

Electron paramagnetic resonance (EPR) was used to study the annealing behavior of the positively charged carbon vacancy (EI5 center) in electron-irradiated 4H-SiC. At ~1000 °C the EPR signal of the defect starts decreasing gradually. Clear ligand hyperfine structure is still observed after... (Read more)

Interfacial defect structures of NO-nitride oxide on Si(100) were characterized by electron spin resonance spectroscopy. We confirmed that the effective g values of the P_b1 center are affected by interfacial nitridation even at a small nitrogen concentration of 5 at. %, while those of the P_b0 center proved to be unchanged. We observed that the shifted P_b1 line appeared gradually with interfacial nitrogen concentration, which suggests that the nitrogen-induced modified structure substitutes for the original P_b1 structure. Angular variations of the shifted P_b1 lines were also significantly different from those of pure oxide. Based on our analysis, we attributed the g value shift of the P_b1 center to dangling bond tilting, caused by the displacement of nearest-neighbor Si atoms. (Read more)

The microscopic process involved with thermal activation of the Mg acceptors in GaN epitaxial films is investigated using electron paramagnetic resonance (EPR) spectroscopy. Samples were heat treated in dry N₂ for 30 min at temperatures between 200 and 1000 °C. Below 850 °C, the... (Read more)

We have observed the nagnetic resonance of conduction electrons in n-type indium antimonide, by the "heating" of the electron kinetic-energy temperature via the slsctron spins. This is the first direct evidence suggesting a contribution of spin-orbit coupling to relaxation in this system. In a steady-state spin-resonance experiment, a power P_S=(M₀=M_Z)H/T₁ is transferred to the systems(reservoirs) towards which the spins relax. Here, M₀ is the equilibrium magnetization, M_Z the component of the magnetization along the magnetic field H, and T1 the relaxation time. The reservoir of interest in our case is the kinetic energy of the eledtrons, and this is detected by an increase in the mobility μ. To our knowledge. this is the first observation of the power flow, due to relaxation, from the spins to a reservoir,applied to the ditection of magnetic resonance of conduction-electron spins. It differs in principle from usual spin-resonance observation methods, which are based on electromagnetic interactions of the spin system, such as the voltage induced in a resonator by the rotating magnetic moment, or again such as power absorption P_S=M_yH_x from the rotating field H_x by the out-of- phase component M_y.Besides providing information on the relaxation mechanism, the present method (that we call "ralaxation" method) should also in some cases by much more sensitive than the usual "electromagnetic" detection methods. (Read more)

Aerosol-assisted vapor phase synthesis aimed at preparation of magnetic semiconductor nanopowders of Ga1−xMnxN is carried out both from aqueous and methanol solution mixtures of gallium nitrate and manganese (II) nitrate. After an additional pyrolysis at 1000 °C under an ammonia flow,... (Read more)

Freeze-drying, as a cryochemical powder processing method is applied in the synthesis of ZnO submicrometer to nanosized powders. The process involves rapid freezing of the sprayed precursor solution, drying under vacuum by sublimation of the solvent and salt decomposition to oxide by thermal... (Read more)

Combining electron paramagnetic resonance measurements with ab initio calculations, we identify the V_CC_Si(Si_CC_Si) complex as a second annealing product of the silicon vacancy via an analysis of resolved carbon hyperfine interactions and of... (Read more)

Shallow N donors in n-type 4H-SiC were studied by electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR). For the N donor at the cubic site (N_k) in 4H-SiC, the hyperfine (hf) constants of the interaction with the nearest-neighbor... (Read more)

Combining efficient density-functional based tight-binding molecular dynamics with ab initio calculations, we show that despite higher formation energies the incorporation of phosphorus at the carbon sublattice is favored by kinetic effects during the annealing processes. Based on the... (Read more)

Optical excitation at 1.7 K with 364-nm laser light produces partial annealing recovery of the damage produced in GaN by 2.5-MeV electron irradiation in situ at 4.2 K. Observed is a reduction in the irradiation-produced 0.95-eV photoluminescence (PL) band, recovery in the visible... (Read more)

Irradiation of GaN by 2.5-MeV electrons in situ at 4.2 K produces a broad photoluminescence (PL) band centered at 0.95 eV. Optical detection of electron paramagnetic resonance (ODEPR) in the band reveals two very similar, but distinct, signals, L5 and L6, which we identify as interstitial... (Read more)

We report results of electron paramagnetic resonance, magnetization, and optical absorption studies of bulk GaN crystals doped with Mn and, for some samples, codoped with Mg acceptor. The experiments performed show that the charge state of the Mn ion in GaN depends on the Fermi level position in the... (Read more)

We report the identification of the vacancy-hydrogen complex in single crystal diamond synthesized by chemical vapor deposition. The S = 1 defect is observed by electron paramagnetic resonance in the negative charge state. The hydrogen atom is bonded to one of the carbon atoms neighboring the... (Read more)

We report the formation processes of interface dangling bonds (P_b centers) during initial oxidation of a clean Si(111) surface using an ultrahigh-vacuum electron-spin-resonance technique. At the oxidation of one or two Si layer(s), the P_b center... (Read more)

We report the observation of a paramagnetic interface defect in thermally oxidized porous n-type doped 4H–SiC/SiO₂. Based on its axial symmetry and resolved hyperfine interactions it is attributed to an sp³ carbon dangling bond center situated... (Read more)

We prepare a microwave electron spin resource (ESR) cavity for detecting a response from a 2DEG in an n-AlGaAs/GaAs. The response is obtained as a change in the longitudinal resistance (Δρ_xx) in v=3 quantum Hall region, particularly as a peak in Δρ_xx for resonance. We use the data of ESR to evaluate the g-factor and the lower bound for dephasing time. The resonance magnetic field suffers from nuclear spin effects via the hyperfine coupling, resulting in the ESR peak shift. We find the ESR peak shift or Overhauser shift decays with two time constants, suggesting the existence of two different origins for the relaxation. (Read more)

The designs of W-band (~95 GHz) Fabry–Pérot microwave resonators for optically detected electron paramagnetic resonance (ODEPR) and electron nuclear double resonance (ODENDOR) as well as the ODEPR/ODENDOR spectrometer are described. The Fabry–Pérot resonator was... (Read more)

We observed two paramagnetic defects in thin films of HfO₂ on silicon with electron spin resonance. Both appear after photoinjecting electrons into the dielectric. Strong spectroscopic evidence links one spectrum to an O2^-" align="middle"> defect. A second spectrum is... (Read more)

Interface defects generated by negative-bias temperature stress (NBTS) in an ultrathin plasma- nitrided SiON/Si(100) system were characterized by using D₂ annealing, conductance-frequency measurements, and electron-spin resonance measurements. D₂ annealing was shown to lower... (Read more)

Electron paramagnetic resonance (EPR) has been used to investigate molecular nitrogen and isolated nitrogen acceptors in single crystals of ZnO. These samples were grown by the seeded chemical vapor transport method with N₂ added to the gas stream. A five-line EPR spectrum is observed at... (Read more)

The oxidation states of Mn in epitaxial GaN films grown by plasma induced molecular beam epitaxy were investigated by electron spin resonance (ESR), elastic recoil detection, superconducting quantum interference device magnetization, and photothermal deflection spectroscopy measurements. Comparison... (Read more)

Tungsten phosphate glasses mixed with the three different modifier oxides, viz. PbO, ZnO and CaO doped with Er2O3 were prepared. The glasses were characterised by X-ray diffraction spectra, electron microscopy and differential thermal analysis. Optical absorption and photoluminescence spectra of... (Read more)

ZnO nanocrystals with diameters ranging from 4 to 50 nm were prepared via a wet chemical method and post-growth annealing treatments. The electron paramagnetic resonance (EPR) spectra of the nanocrystals show the resonance of electron centers with g-value close to that of the shallow donors in bulk... (Read more)

Phosphorus ion implantations of 6H-SiC in the mean phosphorus concentration of the implanted layer of 1 × 1018 cm−3 were performed both at multi-fold energy between 9 and 21 MeV and at 340 keV. In the high-energy implantations at room temperature, 400, 800 and 1200 °C and in the 340... (Read more)

We find that the As-antisite defect in GaAs which is the source of the stable EL2 and metastable EL2^* centers can exist in at least eight different combinations of charge and structural states, twice as many as currently envisaged. In particular, results from first-principles... (Read more)

240 GHz electron paramagnetic resonance (EPR) measurements of as-grown nominally semi-insulating 4H SiC detected two well-separated centers ID1 and ID2. The EPR parameters of ID1 and ID2 coincide with that of EI5 and EI6 centers previously detected in 2-MeV electron-irradiated p-type... (Read more)

We theoretically consider coherence times for spins in two quantum computer architectures, where the qubit is the spin of an electron bound to a P donor impurity in Si or within a GaAs quantum dot. We show that low-temperature decoherence is dominated by spin-spin interactions, through spectral... (Read more)

Electrically detected electron spin resonance (EDESR) signals were acquired as a function of temperature in the 0.3–4.2 K temperature range in an AlGaAs/GaAs multiple-quantum-well sample at the = 1 filling factor at 5.7 T. In the particular sample studied, the linewidth is approximately... (Read more)