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[{"key": "dc.contributor.advisor", "value": "Maasilta, Ilari", "language": null, "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.advisor", "value": "Giazotto, Francesco", "language": null, "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Mastom\u00e4ki, Jaakko", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2017-08-15T07:46:38Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2017-08-15T07:46:38Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2017", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.other", "value": "oai:jykdok.linneanet.fi:1719268", "language": null, "element": "identifier", "qualifier": "other", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/55093", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Ty\u00f6ss\u00e4 selvitettiin menetelm\u00e4\u00e4 suprajohtavien kontaktien liitt\u00e4miseksi ohuen eristekerroksen avulla vahvasti n-seostettuun puolijohtavaan InAs-nanolankaan. Lis\u00e4ksi tutkittiin n\u00e4in luotujen tunneliliitosten soveltamista nanolankojen elektronisen l\u00e4mp\u00f6tilan mittaukseen ja sen j\u00e4\u00e4hdytt\u00e4miseen. Nanolangat oli kasvatettu epitaksiaalisesti kultananopartikkeleiden katalysoimina, ja suprajohtavat kontaktit valmistettiin niiden p\u00e4\u00e4lle k\u00e4ytt\u00e4en tavanomaisia mikrovalmistusmenetelmi\u00e4, elektronisuihkulitografiaa ja -h\u00f6yrystystyst\u00e4. Aluksi langan p\u00e4\u00e4lle h\u00f6yrystettiin ohut kerros titaania ja paksumpi kerros alumiinimangaania, joka oksidoitiin in situ eristekerroksen luomiseksi, ja lopuksi lis\u00e4ttiin suprajohtava alumiinikerros. \n\nTunneliliitokset osoittautuivat l\u00e4hes ideaaleiksi normaali metalli/eriste/suprajohde -liitoksiksi (NIS), joiden normaalitilan resistanssi oli yleens\u00e4 5-20 kilo-ohmia. Alumiinin suprajohtavaksi energia-aukoksi mitattiin noin D = 208 \u00b5eV, ja t\u00e4t\u00e4 arvoa vastaavaa pienemmill\u00e4 biasointij\u00e4nnitteill\u00e4 |eV|<D tunneliliitosten johtavuus oli jopa yli nelj\u00e4 suuruusluokka pienempi kuin normaalitilassa. Ainoa poikkeavuus ideaalista NIS-liitoksesta oli konduktanssik\u00e4yr\u00e4ss\u00e4 j\u00e4nnitteella |eV|~D havaittavat tasanteet, jotka kuitenkin katosivat pieness\u00e4, kohtisuorassa magneettikent\u00e4ss\u00e4, jota sitten k\u00e4ytettiin kaikissa ty\u00f6n my\u00f6hemmiss\u00e4 vaiheissa.\n\nTunneliliitokset soveltuivat hyvin l\u00e4mp\u00f6tilan mittaamiseen noin 200 mK:st\u00e4 yl\u00f6sp\u00e4in, ja niiden herkkyytt\u00e4 oli helppo muuttaa biasointivirtaa s\u00e4\u00e4t\u00e4m\u00e4ll\u00e4. Pienimmill\u00e4\u00e4n herkkyys oli -0,65 mV/K 400 mK:ss\u00e4. Liitoksia hy\u00f6dynnettiin mittaamaan nanolankojen elektronisen j\u00e4\u00e4hdytyksen aikaansaamaa l\u00e4mp\u00f6tilan alenemista, joko parhaimmillaan oli noin 10 mK ymp\u00e4r\u00f6iv\u00e4n l\u00e4mp\u00f6tilan ollessa 250-350 mK. Nanolankoja j\u00e4\u00e4hdytettiin niiden p\u00e4ihin asetetuilla liitoksilla ja l\u00e4mp\u00f6tilaa mitattiin nanolankojen keskelle asetetuilla liitoksilla.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "In this work we investigated methods to contact superconducting leads to heavily n-doped semiconducting InAs nanowires via a thin insulating layer. In addition, we studied the electronic thermometry and refrigeration of the wires by applying the tunnel junctions. The nanowires were grown epitaxially with gold nanoparticles as catalysts, and the superconducting contacts were fabricated on top of them by conventional microfabrication methods, electron-beam lithography and electron-beam evaporation. First, a thin titanium layer and a thicker layer of aluminium manganese were evaporated. The aluminium manganese was oxidized in situ to form an insulating layer, and finally an aluminium layer was added to realize the superconducting contacts.\n\nThe tunnel junctions proved to be nearly ideal normal metal/insulator/superconductor (NIS) junctions with normal state resistance 5-20 kilo-ohms, typically. The superconducting gap of aluminium was measured to be D = 208 \u00b5eV, and the sub-gap conductivity with voltage-biases |eV|<D was suppressed over 4 orders of magnitude compared to the normal state conductivity. The only observed non-ideal properties were the peculiar shoulder structures present in the conductivity curves at voltage bias |eV|~D. The shoulders vanished in a small perpendicular magnetic field, and therefore a small external magnetic field was applied after the initial observation to obtain the further results.\n\nThe tunnel junctions were suitable for thermometry from 200 mK upwards and their sensitivity was easily tunable by a current bias. The sensitivity was at best -0.65 mV/K at temperatures around 400 mK. Thermometer junctions were exploited to measure electronic refrigeration, with an observed electronic temperature reduction of nanowires of at best about 10 mK at bath temperatures 250-350 mK. Nanowires were refrigerated by cooler junctions at their ends, and their temperature was measured by thermometer junctions placed in the middle of them.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted using Plone Publishing form by Jaakko Mastom\u00e4ki (jailmast) on 2017-08-15 07:46:37.421267. Form: Pro gradu -lomake (https://kirjasto.jyu.fi/julkaisut/julkaisulomakkeet/pro-gradu-lomake). JyX data: [jyx_publishing-allowed (fi) =True]", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by jyx lomake-julkaisija (jyx-julkaisija.group@korppi.jyu.fi) on 2017-08-15T07:46:38Z\nNo. of bitstreams: 2\nURN:NBN:fi:jyu-201708153481.pdf: 9554527 bytes, checksum: d98b6c8e758b5173b56371789d296cad (MD5)\nlicense.html: 4839 bytes, checksum: f912534f67c21ab2c49ba1b5586e5200 (MD5)", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2017-08-15T07:46:38Z (GMT). No. of bitstreams: 2\nURN:NBN:fi:jyu-201708153481.pdf: 9554527 bytes, checksum: d98b6c8e758b5173b56371789d296cad (MD5)\nlicense.html: 4839 bytes, checksum: f912534f67c21ab2c49ba1b5586e5200 (MD5)\n Previous issue date: 2017", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "1 verkkoaineisto (78 sivua)", "language": null, "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "suprajohtava tunneliliitos", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "nanoj\u00e4\u00e4hdytys", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "InAs", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "nanolanka", "language": null, "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Superconducting tunnel junctions and nanorefrigeration using InAs nanowires", "language": null, "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-201708153481", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Fysiikan laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Physics", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Soveltava fysiikka", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Applied Physics", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.date.updated", "value": "2017-08-15T07:46:39Z", "language": null, "element": "date", "qualifier": "updated", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": null, "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": "fi", "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": 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