Waveguide-integrated silicon T centres.

The performance of modular, networked quantum technologies will be strongly dependent upon the quality of their quantum light-matter interconnects. Solid-state colour centres, and in particular T centres in silicon, offer competitive technological and commercial advantages as the basis for quantum networking technologies and distributed quantum computing. These newly rediscovered silicon defects offer direct telecommunications-band photonic emission, long-lived electron and nuclear spin qubits, and proven native integration into industry-standard, CMOS-compatible, silicon-on-insulator (SOI) photonic chips at scale. Here we demonstrate further levels of integration by characterizing T centre spin ensembles in single-mode waveguides in SOI. In addition to measuring long spin T1 times, we report on the integrated centres' optical properties. We find that the narrow homogeneous linewidth of these waveguide-integrated emitters is already sufficiently low to predict the future success of remote spin-entangling protocols with only modest cavity Purcell enhancements. We show that further improvements may still be possible by measuring nearly lifetime-limited homogeneous linewidths in isotopically pure bulk crystals. In each case the measured linewidths are more than an order of magnitude lower than previously reported and further support the view that high-performance, large-scale distributed quantum technologies based upon T centres in silicon may be attainable in the near term.

Inductive measurement of optically hyperpolarized phosphorous donor nuclei in an isotopically enriched silicon-28 crystal.

We experimentally demonstrate the first inductive readout of optically hyperpolarized phosphorus-31 donor nuclear spins in an isotopically enriched silicon-28 crystal. The concentration of phosphorus donors in the crystal was 1.5×10(15) cm(-3), 3 orders of magnitude lower than has previously been detected via direct inductive detection. The signal-to-noise ratio measured in a single free induction decay from a 1 cm(3) sample (≈10(15) spins) was 113. By transferring the sample to an X-band ESR spectrometer, we were able to obtain a lower bound for the nuclear spin polarization at 1.7 K of ∼64%. The (31)P-T2 measured with a Hahn echo sequence was 420 ms at 1.7 K, which was extended to 1.2 s with a Carr Purcell cycle. The T1 of the (31)P nuclear spins at 1.7 K is extremely long and could not be determined, as no decay was observed even on a time scale of 4.5 h. Optical excitation was performed with a 1047 nm laser, which provided above-band-gap excitation of the silicon. The buildup of the hyperpolarization at 4.2 K followed a single exponential with a characteristic time of 577 s, while the buildup at 1.7 K showed biexponential behavior with characteristic time constants of 578 and 5670 s.

[Pressure-related dysphonia, recurring pneumonia and supraglottic tumor]. / Belastungsabhängige Dysphonie, rezidivierende Pleuropneumonie und supraglottische Raumforderung.

Urbach-Wiethe syndrome (hyalinosis cutis et mucosae) is an autosomal-recessive inherited disease. It often presents with typical symptoms such as skin lesions (especially in the face and neck area), dyspnea, and maldigestion. Hoarseness is a leading symptom in young children. These manifestations are caused by the assimilation of glycoproteins in mesenchymal tissue. Our case report shows that hoarseness does not necessarily appear only in children, but can also appear later. Furthermore, the assimilation of glycoproteins in the supraglottic area may also cause dysphonia. Due to the varied features of this disease, interdisciplinary check-ups are necessary at regular intervals.

[Value of high-resolution CT in diagnosing acquired cholesteatoma of the middle ear]. / Stellenwert der hochauflösenden CT in der Diagnostik der erworbenen Mittelohrcholesteatome.

In thirty patients with cholesteatomas of the middle ear, high resolution CT of the petrous bone was performed in conjunction with the clinical examination. The extent of the soft tissue process can be demonstrated by CT, but differentiation of the cholesteatoma from the accompanying inflammatory changes is not possible. Typical complications such as destruction of the auditory ossicles, the bony labyrinth, the facial canal, the lateral wall of the attic and the superior and inferior walls of the tympanic cavity are clearly demonstrated. Changes in the mastoids are better demonstrated than by conventional radiography. Using the high contrast and special resolution of modern high resolution CT, this has become the method of choice in the investigation of cholesteatomas of the middle ear.

[High-resolution computed tomography in the diagnosis of bone-destroying processes of the external ear]. / Die hochauflösende Computertomographie in der Abklärung knochendestruierender Prozesse des äusseren Ohres.

Eleven patients with known malignant tumours of the outer ear and three patients with otitis externa maligna were examined by high resolution CT. CT provided accurate information concerning soft tissue infiltration into the parotid or subtemporal tissues, and of the bony destruction in the mastoid, meatus and tympanic cavity. Absolute differentiation between a malignant tumour and otitis cisterna maligna is not possible, not even by high resolution CT.

[High-resolution computed tomography of peripheral facial paralysis]. / Hochauflösende Computertomographie bei peripherer Fazialisparese.

High resolution computer tomographic examinations of the petrous bones were performed on 19 patients with confirmed peripheral facial nerve paralysis. High resolution CT provides accurate information regarding the extent, and usually regarding the type, of pathological process; this can be accurately localised with a view to possible surgical treatment. The examination also differentiates this from idiopathic paresis, which showed no radiological changes. Destruction of the petrous bone, without facial nerve symptoms, makes early suitable treatment mandatory.

[Computed tomography in the preoperative diagnosis of malignant laryngeal tumors]. / Die Computertomographie in der präoperativen Diagnostik von malignen Larynxtumoren.

The pre-operative laryngoscopic and CT findings in the larynx in 50 patients with malignant laryngeal tumours were compared. Laryngoscopy showed an accuracy for T-staging of 78.6% and CT an accuracy of 80%. In addition, CT complemented the endoscopic findings by demonstrating the depth of tumour invasion. The changes in individual anatomical portions of the larynx were compared, using both methods. CT and palpation showed equal specificity for lymph node staging, but CT is markedly superior in sensitivity.

[High-resolution computed tomography in diseases of the inner ear]. / Hochauflösende Computertomographie bei Erkrankungen des Innenohres.

High-resolution CT of the petrous bone was carried out in 259 patients with clinically diagnosed abnormalities of the inner ear; in some the lesions were bilateral. In 62 patients (approximately 20%), the scans showed findings which related to the signs and symptoms. Patients with hearing loss and vestibular neuronitis showed no abnormalities. Amongst the remaining patients, the most common findings were acoustic neuromas (17 cases), cochlear otospongiosis (14 cases), malformations (13 cases) and tumours or cholesteatomas of the labyrinth (13 cases) as well as single rare isolated lesions.

[High-resolution computed tomography in malformations of the cochlear and vestibular organs]. / Hochauflösende Computertomographie bei Missbildungen des Gehör- und Gleichgewichtsorganes.

Twenty-one patients with congenital deformities of the petrous bones were examined by high resolution computed tomography. This allows an accurate description of the extent of the malformation in all parts of the cochlear and vestibular organs; only localised changes in the auditory ossicles, such as fixation of the stapes and changes in the soft tissue portions of the labyrinth, cannot be shown. Improved demonstration of soft tissues while using less radiation makes high resolution CT preferable to conventional polytomography. It is also easier to perform and provides axial projections which are essential for the elucidation of malformations of the middle and inner ear.

[Malignant tumors of the mouth and pharynx--MR tomography with surface coils]. / Malignome der Mundhöhle und des Pharynx--MR-Tomographie mit Oberflächenspulen.

The place of MRT, using surface coils, has been evaluated retrospectively in 27 patients with clinically confirmed malignant tumours of the mouth and pharynx. The extent of the tumour and its relationship to neighbouring structures is well demonstrated. The resolution obtainable by using surface coils is almost as good as that of CT. Soft tissue contrast is better in showing the spread and size of the tumour. A disadvantage of MRT is the inability in most cases to demonstrate bone destruction. Differentiation between residual tumour, recurrence and scarring is possible only occasionally. Quantitative MRT may be expected to lead to improved diagnosis during the course of following up.

Craniometaphyseal dysplasia as a rare cause of a severe neonatal nasal obstruction.

We report on a 2-year-9-month-old boy with the typical features of craniometaphyseal dysplasia with hyperostosis and sclerosis of the cranial vault and mild splaying of the metaphyses. The boy already presented during the neonatal period with the unusual clinical picture of breathing and feeding problems due to severely enlarged and ossified inferior nasal conchae causing obstruction of the nasal lumen.

Quantum information storage for over 180 s using donor spins in a 28Si "semiconductor vacuum".

A quantum computer requires systems that are isolated from their environment, but can be integrated into devices, and whose states can be measured with high accuracy. Nuclear spins in solids promise long coherence lifetimes, but they are difficult to initialize into known states and to detect with high sensitivity. We show how the distinctive optical properties of enriched (28)Si enable the use of hyperfine-resolved optical transitions, as previously applied to great effect for isolated atoms and ions in vacuum. Together with efficient Auger photoionization, these resolved hyperfine transitions permit rapid nuclear hyperpolarization and electrical spin-readout. We combine these techniques to detect nuclear magnetic resonance from dilute (31)P in the purest available sample of (28)Si, at concentrations inaccessible to conventional measurements, measuring a solid-state coherence time of over 180 seconds.

Simultaneous subsecond hyperpolarization of the nuclear and electron spins of phosphorus in silicon by optical pumping of exciton transitions.

We demonstrate a method which can hyperpolarize both the electron and nuclear spins of 31P donors in Si at low field, where both would be essentially unpolarized in equilibrium. It is based on the selective ionization of donors in a specific hyperfine state by optically pumping donor bound exciton hyperfine transitions, which can be spectrally resolved in 28Si. Electron and nuclear polarizations of 90% and 76%, respectively, are obtained in less than a second, providing an initialization mechanism for qubits based on these spins, and enabling further ESR and NMR studies on dilute 31P in 28Si.

Reduction of the linewidths of deep luminescence centers in 28Si reveals fingerprints of the isotope constituents.

Dramatic reductions of the linewidths of well-known deep centers in 28Si reveal "isotopic fingerprints" of the constituents. The approximately 1014 meV Cu center, thought to be either a Cu pair or an isolated Cu, is shown to contain four Cu atoms, and the approximately 780 meV Ag center is shown to contain four Ag. The approximately 944 meV ;{*}Cu center, thought to be a different configuration of a Cu pair, in fact contains three Cu and one Ag, and a new two-Cu two-Ag center is found. The approximately 735 meV center, previously assigned to Fe, actually contains Au and three Cu. This suggests a family of four-atom (Cu, Ag, Au) centers.

Optical detection and ionization of donors in specific electronic and nuclear spin States.

We resolve the remarkably sharp bound exciton transitions of highly enriched 28Si using a single-frequency laser and photoluminescence excitation spectroscopy, as well as photocurrent spectroscopy. Well-resolved doublets in the spectrum of the 31P donor reflect the hyperfine coupling of the electronic and nuclear donor spins. The optical detection of the nuclear spin state, and selective pumping and ionization of donors in specific electronic and nuclear spin states, suggests a number of new possibilities which could be useful for the realization of silicon-based quantum computers.

[Paraganglioma of the nasal cavity]. / Das Paragangliom der inneren Nase.

Extraadrenal paragangliomas are very rarely located in the nose and the nasal sinus. Histological and clinical findings of this tumour are discussed.

[Osteoma of the temporal bone as a rare differential diagnosis of a retroauricular tumor]. / Das Osteom der Schläfenbeinschuppe als seltene Differentialdiagnose eines retroaurikulären Tumors.

Extracanalicular osteomas of the temporal bone represent a rare differential diagnosis of osseous tumours in the ear region in contrast to the common finding of exostoses of the external auditory canal. Basing on a report on a retroauricular osteoma of the squama of the temporal bone treated in the authors' ENT clinic, the morphological and clinical characteristics of this tumour are discussed.

[Intra-arterial chemotherapy as a part of a combination-therapy in carcinoma of the oropharynx]. / Die intraarterielle Chemotherapie als Bestandteil einer Kombinationsbehandlung von Oropharynx-Carcinomen.

Since 1973 75 patients with carcinoma of the oropharynx were treated with regional cytostatic chemotherapy as an initial step of a combined therapy which consists of an follow-up operation and/or radiation. Methotrexate was used in intraarterial short infusions with Leucovorin rescue. The tumor response to i.a. chemotherapy was definite in 80% of the cases, without any negative side effects in the patients who are usually in a reduced general condition. After i.a. chemotherapy to reach a partial remission of the tumor and to create better conditions for the following therapy, we always tried to perform an operation and radiation. With this combination-therapy we reached, in the 1 year NED results as well as in the 3 year survival rate, with 60% resp. 54% better results than in patients who were only radiated after i.a. chemotherapy (43% 1 year NED results resp. 43% 3 year survival rate). A chemotherapy of oropharynx carcinoma is only justified, if other therapy forms follow up, if possible, composed of an operation and radiation. Because of the high rate of response of tumors seen in our patients, the low rate of side effects and the noticeable remission of the tumor-caused complaints it seems to us that the i.a. infusion therapy with methotrexate is a suitable form of chemotherapy for carcinoma of the oropharynx.

[Closure of recurrent perforations of the tympanic membrane by means of cialit-conserved fascia and human fibrin tissue adhesive (author's transl)]. / Verschluss von Rezidivperforationen des Trommelfelles mit cialit-konservierter Faszie und humanem Fibrinkleber.

In 20 patients with recurrent perforations of the tympanic membrane after tympanoplasties the membrane defect was closed by using cialit-conserved temporal fascia and human fibrin tissue adhesive. The defects differed in size from 2 mm up to a subtotal defect. In 19 cases there was increasing vascularisation from the perforation margins towards the transplant centre after 4 weeks. After 8 weeks the connection between the transplant and the surrounding tissue was so tight that tympanometry could be performed using pressures up to 300 mmWS without any damage. Only in 1 case there was an infection. We had to remove the transplant. In comparison with the method of using only human fibrin tissue adhesive to close recurrent perforations, this method has the advantage that even bigger perforations of the tympanic membrane can be closed. The number of recurrencies of perforation also is lessened.

[First experiences with a new method of intra-arterial chemotherapy in tumours of the head and neck (author's transl)]. / Ein Beitrag zur Technik der intraarteriellen Chemotherapie bei Tumoren im Kopf-Hals-Bereich.

The article reports on the use of a new catheter in intraarterial infusion therapy of head and neck tumours. A balloon catheter is inserted into the external carotid artery so that the catheter tip is positioned at the juncture of the artery which provides the blood supply in the tumourous area. Through temporary blockage of the balloon, selective perfusion of the tumour artery with cytostatic drugs is possible. In 10 patients with squamous cell carcinoma of the oral cavity this catheter was used, and the possibilities of this method of selective perfusion explored in contrast to the conventional procedure practised so far.