State-Dependent Optical Lattices for the Strontium Optical Qubit

We demonstrate state-dependent optical lattices for the Sr optical qubit at the tune-out wavelength for its ground state. We tightly trap excited state atoms while suppressing the effect of the lattice on ground state atoms by more than four orders of magnitude. This highly independent control over the qubit states removes inelastic excited state collisions as the main obstacle for quantum simulation and computation schemes based on the Sr optical qubit. Our results also reveal large discrepancies in the atomic data used to calibrate the largest systematic effect of Sr optical lattice clocks.Comment: 6 pages, 4 figures + 6 pages supplemental materia

Biometrijske osobine šnjura pučinara, Trachurus mediterraneus, (Osteichthyes: Carangidae) u srednjem Jadranu

The relationship between morphometric measurements (15) and meristic characters (8) were examined in 237 specimens of Mediterranean horse mackerel (105 females, 101 males and 31 immature specimens) caught in the central Adriatic Sea. The goal of this paper was to investigate: whether there are morphological differences between males and females; the existence of homogenous or heterogeneous morphology stock; changes in morphometric characters with an increase in body length. Morphological differences between males and females were not marked. Modal values specific for Trachurus species morphologic characters, such as number of lateral line scales, maximum height of scales in anterior and posterior part of lateral line, point at which dorsal accessory lateral line is terminated and values of other biometric properties indicated a possible homogeneous morphology stock of T. mediterraneus in the central Adriatic Sea. Changes in some morphometric characters obtained in conjunction with an increase in body length showed that smaller specimens have longer head, anal and ventral fin than adult specimens. On the other hand, with an increase in total length, the fish have larger preorbital and postorbital distance, smaller eye and maximum height of scales in the lateral line than smaller fishes. The negative correlation recorded for the maximum and minimum body depth indicates that the body becomes progressively elongated. The meristic characters of Mediterranean horse mackerel from different Mediterranean and NE Atlantic areas are mostly in agreement with the data in our study.Na 237 primjeraka šnjura pučinara (105 ženki, 101 mužjak i 31 spolno nezrelih jedinki) ulovljenih u srednjem Jadranu analizirana su morfometrijska (15) i meristička obilježja (8). Cilj ove studije bio je istražiti morfološke razlike između mužjaka i ženki, postojanje morfološki homogenog ili heterogenog stoka i promjene morfometrijskih osobina tijekom rasta ribe. Morfološke razlike između mužjaka i ženki nisu izražene. Modalne vrijednosti specifičnih morfoloških obilježja, kao što su broj ljusaka u bočnoj pruzi, najveća visina ljusaka u prednjem i stražnjem dijelu bočne pruge i točka gdje završava dodatna leđna bočna pruga te vrijednosti ostalih biometrijskih osobina ukazuju da u Jadranu vjerojatno obitava morfološki homogena populacija ove vrste. Uočene su promjene morfometrijskih odnosa u vezi s porastom tjelesne dužine. Manji primjerci imaju veću dužinu glave, podrepnu i trbušne peraje nego veći primjerci. S druge strane veće ribe imaju veću predočnu i zaočnu udaljenost, manju veličinu oka i manju visinu ljusaka u bočnoj pruzi u odnosu na manje ribe. Negativna korelacija zabilježena kod najmanje i najveće visine tijela pokazuje da se tijelo ribe progresivno izdužuje. Merističke osobine šnjura pučinara s različitih područja Mediterana i sjeveroistočnog Atlantika uglavnom se podudaraju s podacima dobivenim u ovom radu

Crossed optical cavities with large mode diameters

We report on a compact, ultrahigh-vacuum compatible optical assembly to create large-scale, two-dimensional optical lattices for use in experiments with ultracold atoms. The assembly consists of an octagon-shaped spacer made from ultra-low-expansion glass, to which we optically contact four fused-silica cavity mirrors, making it highly mechanically and thermally stable. The mirror surfaces are nearly plane-parallel which allows us to create two perpendicular cavity modes with diameters $\sim$1 mm. Such large mode diameters are desirable to increase the optical lattice homogeneity, but lead to strong angular sensitivities of the coplanarity between the two cavity modes. We demonstrate a procedure to precisely position each mirror substrate that achieves a deviation from coplanarity of $d = 1(5)$ $\mu$m. Creating large optical lattices at arbitrary visible and near infrared wavelengths requires significant power enhancements to overcome limitations in the available laser power. The cavity mirrors have a customized low-loss mirror coating that enhances the power at a set of relevant wavelengths from the visible to the near infrared by up to three orders of magnitude.Comment: 4 pages, 4 figures, 1 page supplemental materia

Cavity-Enhanced Optical Lattices for Scaling Neutral Atom Quantum Technologies to Higher Qubit Numbers

We demonstrate a cavity-based solution to scale up experiments with ultracold atoms in optical lattices by an order of magnitude over state-of-the-art free space lattices. Our two-dimensional optical lattices are created by power enhancement cavities with large mode waists of 489(8) $\mu$m and allow us to trap ultracold strontium atoms at a lattice depth of 60 $\mu$K by using only 80 mW of input light per cavity axis. We characterize these lattices using high-resolution clock spectroscopy and resolve carrier transitions between different vibrational levels. With these spectral features, we locally measure the lattice potential envelope and the sample temperature with a spatial resolution limited only by the optical resolution of the imaging system. The measured ground-band and trap lifetimes are 18(3) s and 59(2) s, respectively, and the lattice frequency (depth) is long-term stable on the MHz (0.1\%) level. Our results show that large, deep, and stable two-dimensional cavity-enhanced lattices can be created at any wavelength and can be used to scale up neutral-atom-based quantum simulators, quantum computers, sensors, and optical lattice clocks.Comment: 18 pages, 10 figure

[Die bewertung der elektromyogramme der Kaumuskulatur]

Autori, nakon opsežnog uvoda, iznose problem objektivne i jednostavne evaluacije podataka. U radu se iznose podaci iz literature i navode autori, koji su se do sada bavili evaluacijom akcionih potencijala.Donosi se rješenje in teg riranja akcionih potencijala, koje omogućava, načinom još neopisanim u svjetskoj stomatološkoj literaturi, jednostavno i brzo očitavanje dobivenih integriranih podataka akcionih potencijala mastikatorne muskulature. Integrator je izveden tako, da se porast krivulje , koja monotono raste, a koja predstavlja integral promatranog napona, ograničava na jednu vrijednost. Kad se postigne ova vrijednost, proces počinje ispočetka, uz odvajanje jednog električkog impulsa. Za integraciju napona upotrijebljena je pentoda u zasićenom području. Broj impulsa u jedinici vremena daje vrijednost integrala promatrane krivulje napona, u ovom slučaju u volt-sekundama. Ovom se metodom mogućnost greške smanjuje na manje od 3 % . Autori predlažu upotrebu metode, naročito za integriranje suma akcionih potencijala skeletne muskulature.After a detailed introduction the problem from the literature of the evaluation of the action potential authors listed a new solution for the integration of action potentials enabling simple and rapid recording of the obtained integrated data on action potentials of the mastificatory musculature in a manner not yet described in the world dental literature. The integrator operates in such a way that the monotonously rising curve, representing the integral of the voltage is restricted to one value only. When this value is achieved the process starts anew along with emitting of an electrical impulse. For the integration of the voltage a pentode is used in the saturated region. The number o impulses in the time unit gives the value of the integral of the voltage curve under observation, in volt seconds. The accuracy achieved with this method exceeds 3 % . The authors suggests the use of this method especially for the integration of action potential sums for the skeletal musculature.In der ausfuhrlichen Einleitung werden die bisherigen Veroffenlichungen uber die Bewertung der Aktionspotentiale angegeben und das Problem der objektiven und einfachen Bewertung der Angaben vorgebracht. Es wird eine neue Methode der Integrierung der Aktionspotentiale beschrieben, welche auf eine noch nicht beschriebene Weise, eine einfache und rasche Ablesung der integrierten Angaben von Aktionspotentialen der Kaumuskulaturermoglicht. Der Integrator ist so konstruiert dass der Verlauf der monoton steigenden Kurve, welche das Integral der beobachteten Spannungdar stellt, auf einen Wert begrenzt wird . Wenn diese Wert erreicht ist beginnt der Prozess von Neuem, unter Freiwerden eines elektrischen Impulses. Fur die Integrierung der Spannung wurde eine Penthode in gesattigtem Zustand verwendet. Die Anzahl der Impulse in der Zeiteinheit ergibt den Integrationsvvert der beobachteten Spannungskurve, in dišem Falle in Voltsekunden. Diese Methodeerm moglicht es das Fehlbereich unter 3 % heraubzusetzen. Die Autoren befurw orten die Anwendung dieser Methode, insbesondere fur die Integrierung der Summe der Aktionspotentiale der Kaumuskulatur

[Die bewertung der elektromyogramme der Kaumuskulatur]

Autori, nakon opsežnog uvoda, iznose problem objektivne i jednostavne evaluacije podataka. U radu se iznose podaci iz literature i navode autori, koji su se do sada bavili evaluacijom akcionih potencijala.Donosi se rješenje in teg riranja akcionih potencijala, koje omogućava, načinom još neopisanim u svjetskoj stomatološkoj literaturi, jednostavno i brzo očitavanje dobivenih integriranih podataka akcionih potencijala mastikatorne muskulature. Integrator je izveden tako, da se porast krivulje , koja monotono raste, a koja predstavlja integral promatranog napona, ograničava na jednu vrijednost. Kad se postigne ova vrijednost, proces počinje ispočetka, uz odvajanje jednog električkog impulsa. Za integraciju napona upotrijebljena je pentoda u zasićenom području. Broj impulsa u jedinici vremena daje vrijednost integrala promatrane krivulje napona, u ovom slučaju u volt-sekundama. Ovom se metodom mogućnost greške smanjuje na manje od 3 % . Autori predlažu upotrebu metode, naročito za integriranje suma akcionih potencijala skeletne muskulature.After a detailed introduction the problem from the literature of the evaluation of the action potential authors listed a new solution for the integration of action potentials enabling simple and rapid recording of the obtained integrated data on action potentials of the mastificatory musculature in a manner not yet described in the world dental literature. The integrator operates in such a way that the monotonously rising curve, representing the integral of the voltage is restricted to one value only. When this value is achieved the process starts anew along with emitting of an electrical impulse. For the integration of the voltage a pentode is used in the saturated region. The number o impulses in the time unit gives the value of the integral of the voltage curve under observation, in volt seconds. The accuracy achieved with this method exceeds 3 % . The authors suggests the use of this method especially for the integration of action potential sums for the skeletal musculature.In der ausfuhrlichen Einleitung werden die bisherigen Veroffenlichungen uber die Bewertung der Aktionspotentiale angegeben und das Problem der objektiven und einfachen Bewertung der Angaben vorgebracht. Es wird eine neue Methode der Integrierung der Aktionspotentiale beschrieben, welche auf eine noch nicht beschriebene Weise, eine einfache und rasche Ablesung der integrierten Angaben von Aktionspotentialen der Kaumuskulaturermoglicht. Der Integrator ist so konstruiert dass der Verlauf der monoton steigenden Kurve, welche das Integral der beobachteten Spannungdar stellt, auf einen Wert begrenzt wird . Wenn diese Wert erreicht ist beginnt der Prozess von Neuem, unter Freiwerden eines elektrischen Impulses. Fur die Integrierung der Spannung wurde eine Penthode in gesattigtem Zustand verwendet. Die Anzahl der Impulse in der Zeiteinheit ergibt den Integrationsvvert der beobachteten Spannungskurve, in dišem Falle in Voltsekunden. Diese Methodeerm moglicht es das Fehlbereich unter 3 % heraubzusetzen. Die Autoren befurw orten die Anwendung dieser Methode, insbesondere fur die Integrierung der Summe der Aktionspotentiale der Kaumuskulatur

Spectroscopic Investigation of MoO₃-Fe₂O₃-P₂O₅ and SrO-Fe₂O₃-P₂O₅ Glasses I

The relationship between the composition, structure and selected properties for four series of iron phosphate glasses containing MoO3 and SrO has been investigated. The three series of MoO3-Fe2O3-P2O5 glasses were prepared with increasing MoO3 content. In series A the molar Fe/P ratio was constant at 0.67, in series B the O/P ratio was 3.5, whereas, in series C the molar percentages of Fe2O3 was fixed at 40 mol%. In the fourth series, M, SrO was added to maintain the Fe/P ratio constant at 0.67. The structural changes in these glasses have been studied by Raman spectroscopy. The Raman spectra show that MoO3 is incorporated into the phosphate network. However, the structure/properties are strongly influenced by the overall O/P ratio. In glasses with O/P \u3e 3.5 the addition of MoO3 depolymerized some of the bridging oxygens in pyrophosphate units to form isolated (PO4)3− orthophosphate groups. The decrease in glass temperature, Tg, and glass density, D, increase in thermal expansion coefficient, α, and glass density, D, for these glasses are attributed to an increase in the number of weaker P-O-Mo bonds connected to both orthophosphate and pyrophosphate units. The replacement of the stronger P-O-P bonds for the weaker Mo-O-P bonds imparts greater covalency to the network and contributes to the lower bond strength as the bond covalence decreases from P-O to Mo-O. The addition of up to 20 mol% SrO does not produce any changes in the Raman spectra and any further disruption of pyrophosphate chains

Electrical Properties of Sodium Phosphate Glasses Containing Al₂O₃ And/Or Fe₂O₃. Part II

The electrical properties for three series of glasses: xNa2O-(40−x)Al2O3-60P2O5, (20less-than-or-equals, slantxless-than-or-equals, slant35), (NAP); 20Na2O-xAl2O3-(20−x)Fe2O3-60P2O5, (5less-than-or-equals, slantxless-than-or-equals, slant15), (NAFP), and xNa2O-(40−x)Fe2O3-60P2O5, (20less-than-or-equals, slantxless-than-or-equals, slant35), (NFP) glasses were measured by impedance spectroscopy in the frequency range from 1 Hz to 1 MHz and over the temperature range from 303 to 473 K. It was shown (in Part I) that the addition of Fe2O3 has significant effects on the structure of these glasses and Fe ions play a different structural role in phosphate network than that of Al ions. Such effects reflect changes in the origin of electrical conduction. with increasing Fe2O3 content in NAFP and NFP glasses the dc conductivity depends upon distance between iron ions and the activation energy of 53.1 kJmol−1 indicates electronic conduction. On the other hand, the decrease in dc conductivity and activation energy for glasses in NAP series is attributed to the decrease in Na2O content from 35 to 20 mol%. The activation energy varies from 80.1 to 72.4 kJmol−1 for NAP glasses suggesting ionic conduction. The impedance analysis for these glasses shows that the changes in the electrical conduction mechanisms coincide with the changes in the structure