32 research outputs found
Kaksikubittiportit mikroaaltofotonisessa kvanttitietokoneessa
Building a scalable quantum computer is one of the greatest challenges of this century. A quantum computer should be able to execute quantum algorithms which promise great speed up in solving certain computational problems.
Microwave photons in superconducting circuits offer a promising platform for quantum computing due to their long coherence times, and the ease of their generation and control. Single-qubit quantum gates are implemented with conventional microwave components. However, implementing entangling two-qubit gates for photonic qubits is considerably difficult because photons do not interact with each other naturally.
In this thesis, we investigate the effective interactions between photons mediated by superconducting qubits. Especially, the nonlinear effects in the photonic states generated by these interactions are studied.
Based on the analysis of the scattering properties of the system, we present a design for a nonlinear phase shifter device, which yields a photon-number-dependent phase shift in the transmitted photons. Furthermore, we show how entangling two-qubit gates can be implemented using the presented nonlinear phase shifter.Yksi vuosisatamme suurimmista haasteista on skaalautuvan kvanttitietokoneen rakentaminen. Kvanttitietokoneen tulisi pystyä suorittamaan kvanttialgoritmeja, jotka mahdollistavat tietyille laskennallisille ongelmille klassisia vastineita huomattavasti nopeamman ratkaisemisen.
Mikroaaltofotonit suprajohtavissa piireissä tarjoavat lupaavan alustan kvanttilaskennalle niiden suhteellisen pitkien koherenssiaikojen sekä niiden luomisen ja muokkaamisen helppouden vuoksi. Yksikubittiportteja on mahdollista toteuttaa käyttäen tavanomaisia mikroaaltokomponentteja. Lomittavien kaksikubittiporttien toteuttaminen on kuitenkin erityisen haastavaa, sillä fotonit eivät vuorovaikuta keskenään luonnollisesti.
Tässä työssä tutkimme mikroaaltofotonien kokemaa efektiivistä vuorovaikutusta, jonka välittäjänä toimivat suprajohtavat kubitit. Tutkimme erityisesti näiden vuorovaikutusten tuottamia epälineaarisia vaikutuksia fotonisissa tiloissa.
Perustuen tällaisen systeemin sirontaominaisuuksiin, esittelemme mallin epälineaariselle vaiheensiirtimelle, joka tuottaa fotonien lukumäärästä riippuvan vaiheensiirron systeemin läpäiseville fotoneille. Lisäksi näytämme kuinka tietyt lomittavat kaksikubittiportit voidaan toteuttaa käyttämällä esiteltyä epälineaarista vaiheensiirrintä
Three-dimensional skyrmions in spin-2 Bose-Einstein condensates
We introduce topologically stable three-dimensional skyrmions in the cyclic and biaxial nematic phases of a spin-2 Bose-Einstein condensate. These skyrmions exhibit exceptionally high mapping degrees resulting from the versatile symmetries of the corresponding order parameters. We show how these structures can be created in existing experimental setups and study their temporal evolution and lifetime by numerically solving the three-dimensional Gross-Pitaevskii equations for realistic parameter values. Although the biaxial nematic and cyclic phases are observed to be unstable against transition towards the ferromagnetic phase, their lifetimes are long enough for the skyrmions to be imprinted and detected experimentally.Peer reviewe
Sideband thermometry of ion crystals
Coulomb crystals of cold trapped ions are a leading platform for the
realisation of quantum processors and quantum simulations and, in quantum
metrology, for the construction of optical atomic clocks and for fundamental
tests of the Standard Model. For these applications, it is not only essential
to cool the ion crystal in all its degrees of freedom down to the quantum
ground state, but also to be able to determine its temperature with a high
accuracy. However, when a large ground-state cooled crystal is interrogated for
thermometry, complex many-body interactions take place, making it challenging
to accurately estimate the temperature with established techniques. In this
work we present a new thermometry method tailored for ion crystals. The method
is applicable to all normal modes of motion and does not suffer from a
computational bottleneck when applied to large ion crystals. We test the
temperature estimate with two experiments, namely with a 1D linear chain of 4
ions and a 2D crystal of 19 ions and verify the results, where possible, using
other methods. The results show that the new method is an accurate and
efficient tool for thermometry of ion crystals.Comment: 12+5 pages, 9+2 figures, Fig.3(b) was correcte
PENERAPAN DATA MINING UNTUK ANALISIS DATA BENCANA MILIK BNPB MENGGUNAKAN ALGORITMA K-MEANS DAN LINEAR REGRESSION
Indonesia memiliki sejarah kejadian bencana alam yang cukup banyak, diantaranya adalah tsunami, gempa bumi, tanah longsor, kekeringan, banjir, letusan gunung berapi, dan sebagainya. Salah satu penyebab banyaknya potensi kejadian bencana alam di Indonesia adalah letak Indonesia yang berada di pertemuan lempeng – lempeng Eurasia, Indo-Australia dan Pasifik. Pertemuan lempeng dalam jangka panjang akan menghimpun energi yang suatu waktu akan lepas dan dapat menghasilkan bencana. Pengetahuan teknologi dan informasi pada saat ini sedang mengalami perkembangan yang pesat.Informasi tentang jumlah kejadian bencana alam dibutuhkan untuk penanggulangan bencana.Pengolahan data bencana alam yang umum dilakukan yaitu menggunakan teknik data mining, karena metode ini dianggap mampu menjadi solusi atas permasalahan penanggulangan bencana alam. Oleh karena itu, dalam penelitian ini membahas tentang pengelompokkan jumlah data bencana dan prediksi data bencana yang akan terjadi 5 tahun kedepan menggunakan teknik data mining. Algoritmadata mining yang digunakan adalah K-Means untuk clustering dan Linear Regression untuk prediksi data bencana.Kata kunci: Clustering, Data Bencana Alam, Data Mining, Linear Regression, WEK
RVD induction and autologous stem cell transplantation followed by lenalidomide maintenance in newly diagnosed multiple myeloma: a phase 2 study of the Finnish Myeloma Group
Autologous stem cell transplantation (ASCT) combined with novel agents is the standard treatment for transplant-eligible, newly diagnosed myeloma (NDMM) patients. Lenalidomide is approved for maintenance after ASCT until progression, although the optimal duration of maintenance is unknown. In this trial, 80 patients with NDMM received three cycles of lenalidomide, bortezomib, and dexamethasone followed by ASCT and lenalidomide maintenance until progression or toxicity. The primary endpoint was the proportion of flow-negative patients. Molecular response was assessed if patients were flow-negative or in stringent complete response (sCR). By intention to treat, the overall response rate was 89%. Neither median progression-free survival nor overall survival (OS) has been reached. The OS at 3 years was 83%. Flow-negativity was reached in 53% and PCR-negativity in 28% of the patients. With a median follow-up of 27 months, 29 (36%) patients are still on lenalidomide and 66% of them have sustained flow-negativity. Lenalidomide maintenance phase was reached in 8/16 high-risk patients but seven of them have progressed after a median of only 6 months. In low- or standard-risk patients, the outcome was promising, but high-risk patients need more effective treatment approach. Flow-negativity with the conventional flow was an independent predictor for longer PFS
The Other Voice: A preparation for a journey
Opinnäytetyön taiteellinen osio A preparation for a journey on eri materiaaleista valmistetuista elementeistä rakennettu installaatio. Installaation pyrkimyksenä oli luoda yhtä aikaa sekä tila että tapahtuma. Materiaalivalinnat ja työstömenetelmät olivat tärkeä osa installaation teemojen käsittelyssä.
Kaikki installaation materiaalit ovat perinteisiä kuvanveiston materiaaleja. Teoksen yksi tarkoitus on heijastaa tekijän koulutuksessaan oppimia menetelmiä. Eri elementtien työstämisessä ei käytetty lainkaan koneita vaan kaikki tehtiin käsi-työkaluin. Installaation lopullinen kokonaisuus ja esitystapa jätettiin auki näytte-lyn rakentamiseen asti. Kirjallinen osio The Other Voice: A preparation for a journey käy läpi runouden ominaisuuksia, vertailee runoutta ja kuvanveistoa, keskustelee kauneudesta sekä avaa installaation tekemisen lähtökohtia, haasteita ja valintoja.
Installaatio on käsitellyt ja muokannut sen taustalla olevat kokemukset ja ajatukset niin pitkälle kuin mahdollista. Se on tekijälleen mielenkiintoinen kokonai-suus, jossa eri elementit yhdessä luovat sekä intiimin ja runollisen että tilallisen ja tarinallisen kokemuksen.The thesis is an installation, which is constructed from many elements of different materials. The aim of the installation was to create, at the same time, both a space and an event. The choice of materials and the methods of working played an important role in connection to the themes of the installation.
The materials used in the installation are all traditional materials for sculpture. The installation also displays the methods of sculpture, which the education has provided. The work for the installation was done by hand tools only. No machines were used for the work. The final assembly of the different elements and their presentation was left open until the building of the exhibition. The written part points out some qualities of poetry, compares poetry and sculpture, makes a short aesthetic analysis and brings light to the aims, challenges and decisions in the making of the installation.
The installation has dealt deep with and shaped further the experiences and thoughts behind it. The result is an interesting whole, in which the different elements create both intimate and poetic, and spatial and narrative experience