Characterizing the local vectorial electric field near an atom chip using Rydberg state spectroscopy

We use the sensitive response to electric fields of Rydberg atoms to characterize all three vector components of the local electric field close to an atom-chip surface. We measured Stark-Zeeman maps of $S$ and $D$ Rydberg states using an elongated cloud of ultracold Rubidium atoms ($T\sim2.5$ $\mu$K) trapped magnetically $100$ $\mu$m from the chip surface. The spectroscopy of $S$ states yields a calibration for the generated local electric field at the position of the atoms. The values for different components of the field are extracted from the more complex response of $D$ states to the combined electric and magnetic fields. From the analysis we find residual fields in the two uncompensated directions of $0.0\pm0.2$ V/cm and $1.98\pm0.09$ V/cm respectively. This method also allows us to extract a value for the relevant field gradient along the long axis of the cloud. The manipulation of electric fields and the magnetic trapping are both done using on-chip wires, making this setup a promising candidate to observe Rydberg-mediated interactions on a chip.Comment: 8 pages, 5 figure

Rydberg dressing of a one-dimensional Bose-Einstein condensate

We study the influence of Rydberg-dressed interactions in a one-dimensional (1D) Bose-Einstein condensate (BEC). We show that a 1D geometry offers several advantages over a three-dimensional geometry for observing BEC Rydberg dressing. The effects of dressing are studied by investigating collective BEC dynamics after a rapid switch-off of the Rydberg dressing interaction. The results can be interpreted as an effective modification of the s-wave scattering length. We include this modification in an analytical model for the 1D BEC and compare it to numerical calculations of Rydberg dressing under realistic experimental conditions.</p

Signatures of self-organized criticality in an ultracold atomic gas

Self-organized criticality is an elegant explanation of how complex structures emerge and persist throughout nature, and why such structures often exhibit similar scale-invariant properties. Although self-organized criticality is sometimes captured by simple models that feature a critical point as an attractor for the dynamics, the connection to real-world systems is exceptionally hard to test quantitatively. Here we observe three key signatures of self-organized criticality in the dynamics of a driven–dissipative gas of ultracold potassium atoms: self-organization to a stationary state that is largely independent of the initial conditions; scale-invariance of the final density characterized by a unique scaling function; and large fluctuations of the number of excited atoms (avalanches) obeying a characteristic power-law distribution. This work establishes a well-controlled platform for investigating self-organization phenomena and non-equilibrium criticality, with experimental access to the underlying microscopic details of the system

Two-Electron Excitation of an Interacting Cold Rydberg Gas

We report the creation of an interacting cold Rydberg gas of strontium atoms. We show that the excitation spectrum of the inner valence electron is sensitive to the interactions in the Rydberg gas, even though they are mediated by the outer Rydberg electron. By studying the evolution of this spectrum we observe density-dependent population transfer to a state of higher angular momentum l. We determine the fraction of Rydberg atoms transferred, and identify the dominant transfer mechanism to be l-changing electron-Rydberg collisions associated with the formation of a cold plasma

“Work and Production Exhibition” in-between 1950-1970 art environment

Bu araştırmanın amacı, Türk sanatının yüzyıllara dayanan figüratif geleneğinin temel eğilimlerinin neler olduğunu belirli araştırma soruları yoluyla ortaya koymak ve buradan hareketle, Batı’ya dönük sanatsal değişimin temel göstergelerini anlamlandırmaktır. Bu amaçla araştırmanın her bölümünde, içeriğin kapsamına yönelik araştırma soruları sorularak kuramsal bir çözümleme yöntemi uygulanmıştır. Araştırmanın Türk sanatında geleneğe bağlılık ve modernleşme arasındaki gerilime tanıklık eden olaylardan biri olarak ele alınan “İş ve İstihsal Sergisi”, bu dönüşümün önemli göstergelerinden biri olarak bağlamın merkezine oturtulmuştur. 1954 yılında, Yapı ve Kredi Bankası’nın onuncu yıldönümü nedeniyle düzenlediği ‘’İş ve İstihsal’’ konulu resim ve afiş yarışması, birçok anlamda Türkiye’de modern sanattan çağdaş sanata geçişin ilk ödüllendirildiği jürili etkinlik olarak bilinmektedir. Etkinlik, dönemin toplumsal ve siyasi ortamı bağlamında etkileşimler ve değişimler gibi çeşitli başlıklarda ele alınmıştır. Yarışmada Aliye Berger’in birinci olması nedeniyle soyut sanatın destek bulması ve Lhote Kübizmini (Anadolu Kübizmi) savunan akademik anlayışın güç kaybetmeye başlaması, yarışmanın Türk sanatını etkileyen önemli sonuçları arasındadır. Araştırmanın sonuç bölümü, girişte bağlamı oluşturan soruların bölümler arasında kurulan bağlantıları üzerinden yazılmıştır. Bu sonuçlar arasında; Türk sanatında vi geleneğin oluşumu, değişen ve değişmeyen kültürel değerler, Batıyla kurulan sanatsal iletişim, soyut sanatın Avrupa ve Amerika’daki gelişimi, Türk sanatında Batıya dönük sanat anlayışının oluşumu, ve serginin değerlendirilmesi ve Türk sanatı açısından önemi gibi kısımlar bulunmaktadır. Bunlardan ayrıca önem taşıyanlar, sergi bağlamında yaşanan sanatsal değişimler, serginin Türk sanatı açısından önemi ve 1950-1970 sanat ortamıdır. 1950-70’li yıllar, serbest ekonomi ve politik ortamın olanaklarından yararlanan bankalar ve galeriler gibi özel kurumların, Cumhuriyet döneminde sanata devlet tarafından verilen destek ve girişimleri sahiplendikleri bir dönemdir. Bu yıllar aynı zamanda, bu özel kurumların sanata mekân bulunması için çaba içerisinde oldukları ve sanatçıya teşvik edici girişimlerde bulundukları dönüşüm yılları olmuştur. Kurumların bilinçli koleksiyonerlik ve galericilik çabaları, İstanbul dışında İzmir ve Ankara’da da sanat faaliyetleri konusunda öncü niteliktedir. Türk sanatı anlamında kimlik kaygılarının gelenekle ilişkisinin şekillendiği ve bireysellik arayışlarıyla sergilenme imkanı bulduğu bu dönem aynı zamanda özel kurumlar olan galerilerin arttığı, örgütlendiği ve galericiliğin bir meslek haline geldiği dönem olmuştur.The purpose of this research, to reveal the basic tendencies of the figurative tradition of Turkish art that goes back to centuries, through certain research questions and from this point of view to understand the main indicators of artistic change towards the West. For this purpose, a theoretical analysis method was applied by asking the research questions about the content of each part of the research. The “Work and Employment Exhibition”, which is considered as one of the events that witnessed the tension between the commitment to tradition and modernization in Turkish art, has been placed at the center of the context as one of the important indicators of this transformation. In 1954, painting and poster competetion that organized by Yapi ve Kredi Bank due to the tenth anniversary of " Work and Employment Exhibition", is known with many respects such as the first jury awarded event of the transition from modern art to contemporary art in Turkey. The activity has been discussed in various topics such as interactions and changes in the context of the social and political environment of the period. As Aliye Berger came first in the competition, gaining support abstract art and the academic understanding defending Lhote Cubism viii (Anatolian Cubism) begining to lose power, are of the important results of the contest affecting Turkish art. The conclusion section of the research, the questions that make up the context in the introduction are structured over the connections between the all sections. Among these results; the formation of tradition in Turkish art, changing and unchanging cultural values, Artistic communication with the West, the development of abstract art in Europe and America, the formation of understanding in Turkish art facing Western art, and the evaluation of the exhibition and its importance for Turkish art. Of these, also important, artistic changes in the context of the exhibition, the importance of the exhibition in terms of Turkish art and 1950-1970 art environment. Private institutions such as galleries and banks benefiting from the opportunities of free economy and political environment, possesed the initiatives and supports for art, provided by government in the Republican period, in 1950-70s. These years were also transformation years, which these private institutions endeavored to find a place for art and made attempts to encourage the artist in. Conscious collecting and efforts of institutions for art dealing, are also pioneer initiatives in art activities in Izmir and Ankara besides Istanbul. It was the period, in which the relationship between identity concerns and tradition shaped by means of Turkish art, organizers and galleries became a profession and also the galleries, which were private institutions increased, as well

Number-resolved imaging of excited-state atoms using a scanning autoionization microscope

We report on a scanning microscopy technique for atom-number-resolved imaging of excited-state atoms. A tightly focused laser beam leads to local autoionization and the resulting ions are counted electronically. Scanning the beam across the cloud builds up an image of the density distribution of excited atoms, with access to the full counting statistics at each spatial sampling point and an overall detection efficiency of 21% . We apply this technique to the measurement of a spatially inhomogeneous electric field with a spatial resolution of 50 μ m and a sensitivity to electric-field gradients of 0.04 V cm −2