From quantum metrology to applications

Emma Mykkänen

From quantum metrology to applications

Julkaisun otsikon käännös: Kvanttimittatekniikasta sovelluksiin

Emma Mykkänen

Teknillisen fysiikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

On tärkeää, että mittaustulokset eivät riipu paikasta tai ajasta. Tämä varmistetaan käyttämällä kansainvälistä mittayksikköjärjestelmää (SI), joka on toteuteuttu primääristen mittanormaalien avulla. Nämä normaalit ovat laitteita, joilla voi mitata tai tuottaa mittayksikköä vastaavan suureen arvon, ja joita ei tarvitse kalibroita toista saman yksikön toteutusta vastaan. Tässä väitöskirjassa tutkittiin mahdollisuutta luoda kvanttimittanormaalit kelvinille ja ampeerille. Lisäksi kehitettiin laitteita, jotka liittyvät tähän tutkimukseen tai ovat sen mahdollistajia. Coulombin saartoon perustuvaa lämpömittaria tutkittiin mahdollisena primäärisenä mittanormaalina kelvinille: Sille rakennettiin mittausympäristö, jossa lämpötila voitiin määrittää Boltzmannin vakion ja jäljitettävästi mitatun jännitteen avulla. Lisäksi sitä verrattiin PLTS-2000 lämpötila-asteikkoon sekä kahteen muuhun Boltzmannin vakioon perustuvaan primääriseen lämpömittariin. Ampeerin kvanttimittanormaalitutkimukseen sovellettiin kahta eri ilmiötä: elektronien tunneloitumista suprajohde - eriste - normaalimetalli (NIS) -liitoksissa ja kvanttivaihehyppyjä suprajohtavissa nanolangoissa. Väitöskirjan aikana jälkimmäisiä havaittiin uudessa materiaalissa, molybdeenisilisidissä. Teoreettisesti on todistettu, että suprajohteen korkea normaalitilan resistiivisyys on edullista kvanttivaihehyppyihin perustuvien normaalien toteutukselle. Tällainen resistiivisyys voidaan saavuttaa kyseisessä materiaalissa. Virran kvanttimittanormaalin aikaansaamat signaalit ovat pieniä (suurimmillaan nanoampeereja) ja tästä syystä ylimääräinen kohina voi kasvattaa tarkkoihin mittauksiin tarvittavaa kestoa merkittävästi. Toisaalta taas, jos kohinafotonien energia on suuri, ne voivat rikkoa Cooperin pareja tai aiheuttaa epätoivottuja tunneloitumisia, mikä heikentää laitteiden tarkkuutta. Ensimmäinen näistä ongelmista ratkaistiin mittauskytkennän johdotusta parantamalla ja jälkimmäistä varten tutkittiin kahta kohinasuodatinta. NIS-liitoksiin perustuvien laitteiden, mm. kvanttivirtanormaalien, tutkimuksessa saavutettua tietämystä hyödynnettiin kahdessa sovelluksessa: kohina-antureissa ja jäähdyttimissä. Jälkimmäisiä käytettiin jäähdyttämään millimetriskaalan piisiruja. Niissä jäähdytys perustui fononien liikkuvuuden rajoittamiseen toisin kuin aiemmin tutkituissa NIS-jäähdyttimissä. Samassa yhteydessä todettiin simulointeja apuna käyttäen, että jäähdytys 1,5 K:stä aina sataan millikelviniin asti on saavutettavissa oleva päämäärä.

Julkaisun otsikon käännös	Kvanttimittatekniikasta sovelluksiin
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Pekola, Jukka, Vastuuprofessori Kemppinen, Antti, Ohjaaja, Ulkoinen henkilö
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-8275-2
Sähköinen ISBN	978-952-60-8276-9
Tila	Julkaistu - 2018
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

kvanttifysiikka
mittatekniikka
tunneliliitokset
kvanttimittanormaalit
kelvin
ampeeri
jäähdytys
kohinasuodatus- ja detektointi

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-8276-9Lisenssi: Määrittelemätön

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Aalto-yliopisto
Laitteistot/tilat: Facility
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Repo, P. (Manager) & Rissanen, A. (Other)
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@phdthesis{efc8668d0c8b4cc88fd1820a3feb7eb3,

title = "From quantum metrology to applications",

abstract = "It is important that measurements produce predictable and reproducible results irrespective of time and location. This is enabled by the International System of Units (SI), which is realized through primary standards: devices that can either measure or produce a known value of a quantity without calibration against any other standard for quantity of the same kind. This thesis explores quantum standards for the ampere and the kelvin, and devices that are byproducts of this research or enablers for the devices spawning from it. Coulomb blockade thermometer (CBT) was investigated as a possible realization of the kelvin at low temperatures. We constructed a setup, where temperature could be determined through Boltzmann constant and traceable voltage measurements. The CBT was also compared to the PLTS-2000 temperature scale and to two other Boltzmann constant based primary thermometers. Two different quantum phenomena were studied in the context of the ampere: single-electron tunneling in superconductor -- insulator -- normal metal (NIS) junctions and quantum phase slips (QPS) in superconducting nanowires. We observed QPS in novel material: molybdenium silicide (MoSi). It has been theoretically predicted that high normal state resistivity would be beneficial for the QPS based current standard. This resistivity can be achieved in MoSi. Since the novel standards for the ampere would produce relatively small currents (up to nanoampere), low frequency noise can increase the measurement times from hours to weeks. On the other hand, high frequency noise can initiate unwanted tunnelings and degrade the accuracy of devices. The low frequency noise problems were tackled by proper cabling and two filters were characterized in the high frequency range by NIS based detectors. Finally we utilized the understanding of NIS systems, based on research aiming at realization of the quantum current standard, in two other applications: noise detectors and coolers. We demonstrated NIS-based cooling of a mm-scale object by silicon-aluminium junctions. The cooling was enabled by phonon transmission bottleneck. We also analyzed by simulations that electric cooling from 1.5 K to 100 mK is a realistic goal.",

keywords = "quantum physics, metrology, tunnel junctions, quantum standards, kelvin, ampere, electric cooling, noise filtering and detection, kvanttifysiikka, mittatekniikka, tunneliliitokset, kvanttimittanormaalit, kelvin, ampeeri, j{\"a}{\"a}hdytys, kohinasuodatus- ja detektointi, quantum physics, metrology, tunnel junctions, quantum standards, kelvin, ampere, electric cooling, noise filtering and detection",

author = "Emma Mykk{\"a}nen",

year = "2018",

language = "English",

isbn = "978-952-60-8275-2",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "216",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - From quantum metrology to applications

AU - Mykkänen, Emma

PY - 2018

Y1 - 2018

N2 - It is important that measurements produce predictable and reproducible results irrespective of time and location. This is enabled by the International System of Units (SI), which is realized through primary standards: devices that can either measure or produce a known value of a quantity without calibration against any other standard for quantity of the same kind. This thesis explores quantum standards for the ampere and the kelvin, and devices that are byproducts of this research or enablers for the devices spawning from it. Coulomb blockade thermometer (CBT) was investigated as a possible realization of the kelvin at low temperatures. We constructed a setup, where temperature could be determined through Boltzmann constant and traceable voltage measurements. The CBT was also compared to the PLTS-2000 temperature scale and to two other Boltzmann constant based primary thermometers. Two different quantum phenomena were studied in the context of the ampere: single-electron tunneling in superconductor -- insulator -- normal metal (NIS) junctions and quantum phase slips (QPS) in superconducting nanowires. We observed QPS in novel material: molybdenium silicide (MoSi). It has been theoretically predicted that high normal state resistivity would be beneficial for the QPS based current standard. This resistivity can be achieved in MoSi. Since the novel standards for the ampere would produce relatively small currents (up to nanoampere), low frequency noise can increase the measurement times from hours to weeks. On the other hand, high frequency noise can initiate unwanted tunnelings and degrade the accuracy of devices. The low frequency noise problems were tackled by proper cabling and two filters were characterized in the high frequency range by NIS based detectors. Finally we utilized the understanding of NIS systems, based on research aiming at realization of the quantum current standard, in two other applications: noise detectors and coolers. We demonstrated NIS-based cooling of a mm-scale object by silicon-aluminium junctions. The cooling was enabled by phonon transmission bottleneck. We also analyzed by simulations that electric cooling from 1.5 K to 100 mK is a realistic goal.

AB - It is important that measurements produce predictable and reproducible results irrespective of time and location. This is enabled by the International System of Units (SI), which is realized through primary standards: devices that can either measure or produce a known value of a quantity without calibration against any other standard for quantity of the same kind. This thesis explores quantum standards for the ampere and the kelvin, and devices that are byproducts of this research or enablers for the devices spawning from it. Coulomb blockade thermometer (CBT) was investigated as a possible realization of the kelvin at low temperatures. We constructed a setup, where temperature could be determined through Boltzmann constant and traceable voltage measurements. The CBT was also compared to the PLTS-2000 temperature scale and to two other Boltzmann constant based primary thermometers. Two different quantum phenomena were studied in the context of the ampere: single-electron tunneling in superconductor -- insulator -- normal metal (NIS) junctions and quantum phase slips (QPS) in superconducting nanowires. We observed QPS in novel material: molybdenium silicide (MoSi). It has been theoretically predicted that high normal state resistivity would be beneficial for the QPS based current standard. This resistivity can be achieved in MoSi. Since the novel standards for the ampere would produce relatively small currents (up to nanoampere), low frequency noise can increase the measurement times from hours to weeks. On the other hand, high frequency noise can initiate unwanted tunnelings and degrade the accuracy of devices. The low frequency noise problems were tackled by proper cabling and two filters were characterized in the high frequency range by NIS based detectors. Finally we utilized the understanding of NIS systems, based on research aiming at realization of the quantum current standard, in two other applications: noise detectors and coolers. We demonstrated NIS-based cooling of a mm-scale object by silicon-aluminium junctions. The cooling was enabled by phonon transmission bottleneck. We also analyzed by simulations that electric cooling from 1.5 K to 100 mK is a realistic goal.

KW - quantum physics

KW - metrology

KW - tunnel junctions

KW - quantum standards

KW - kelvin

KW - ampere

KW - electric cooling

KW - noise filtering and detection

KW - kvanttifysiikka

KW - mittatekniikka

KW - tunneliliitokset

KW - kvanttimittanormaalit

KW - kelvin

KW - ampeeri

KW - jäähdytys

KW - kohinasuodatus- ja detektointi

KW - quantum physics

KW - metrology

KW - tunnel junctions

KW - quantum standards

KW - kelvin

KW - ampere

KW - electric cooling

KW - noise filtering and detection

M3 - Doctoral Thesis

SN - 978-952-60-8275-2

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

From quantum metrology to applications

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

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