From the point of view of the electromagnetic interaction, empirical descriptions of the nucleus involve only a few parameters, one of the most important being the nuclear charge radius. This has been well measured for ground state nuclei, but it is difficult to measure for excited states, since they decay too quickly for conventional methods to be used. We study the atomic transitions in muonic ^{90}Zr and find that the nuclear charge radius of the first excited state can be inferred by measuring the gamma emissions from certain transitions. We find that with 1keV photon resolution, we can infer a difference between the charge radius of the nuclear ground state and first excited state as small as 0.13%. We will work in units where h = c = 4\pi\epsilon_0 = 1 so that e^2 = \alpha \approx 1/137 (unless otherwise specified). Mass, momentum, and energy will have units of eV, whereas distances will be given in eV^{-1}. In qualitative discussion, we will sometimes revert to discussing distances in meters due to the familiarity of typical scales (e.g. nuclear radius, Bohr radius). When working with 4-vectors in Minkowski space, we use the metric convention (+,-,-,-). / Graduate

The author of this thesis concentrates his attention on quantum optical properties of some artificial electromagnetic media, such as quantum coherent atomic vapors (various multilevel electromagnetically induced transparency vapors) and negative refractive index materials, and suggests some possible ways to manipulate wave propagations inside the artificial electromagnetic materials based on quantum coherence and quantum vacuum effects. In Chapters 1 and 2, the author reviews the previous papers on quantum coherence as well as the relevant work such as electromagnetically induced transparency (EIT), atomic population trapping and their various applications. The basic concepts of quantum coherence (atomic phase coherence, quantum interferences within atomic energy levels) and quantum vacuum are introduced, and the theoretical formulations for treating wave propagations in quantum coherent media are presented. In Chapter 3, the author considers three topics on the manipulation of light propagations via quantum coherence and quantum interferences: i) the evolutional optical behaviors (turn-on dynamics) of a four-level N-configuration atomic system is studied and the tunable optical behavior that depends on the intensity ratio of the signal field to the control field is considered. Some typical photonic logic gates (e.g. NOT and NOR gates) are designed based on the tunable four-level optical responses of the N-configuration atomic system; ii) the destructive and constructive quantum interferences between two control transitions (driven by the control fields) in a tripod-type four-level system is suggested. The double-control quantum interferences can be utilized to realize some photonic devices such as the logic-gate devices, e.g., NOT, OR, NOR and EXNOR gates; iii) some new quantum coherent schemes (using EIT and dressed-state mixed-parity transitions) for realizing negative refractive indices are proposed. The most remarkable characteristic (and advantage) of the present scenarios is such that the isotropic left-handed media (with microscopic structure units at the atomic level) in the optical frequency band can be achieved. Quantum vacuum (the ground state of quantized fields) can exhibit many interesting effects. In Chapter 4, we investigate two quantum-vacuum effects in artificial materials: i) the anisotropic distribution of quantum-vacuum momentum density in a moving electromagnetic medium; ii) the angular momentum transfer between quantum vacuum and anisotropic medium. Such quantum-vacuum macroscopic mechanical effects could be detected by current technology, e.g., the so-called fiber optical sensor that can measure motion with nanoscale sensitivity. We expect that these vacuum effects could be utilized to develop sensitive sensor techniques or to design new quantum optical and photonic devices.In Chapter 5, the author suggests some interesting effects due to the combination of quantum coherence and quantum vacuum, i.e., the quantum coherent effects, in which the quantum-vacuum fluctuation field is involved. Two topics are addressed: i) spontaneous emission inhibition due to quantum interference in a three-level system; ii) quantum light-induced guiding potentials for coherent manipulation of atomic matter waves (containing multilevel atoms). These quantum guiding potentials could be utilized to cool and trap atoms, and may be used for the development of new techniques of atom fibers and atom chips, where the coherent manipulation of atomic matter waves is needed.In Chapter 6, we conclude this thesis with some remarks, briefly discuss new work that deserves further consideration in the future, and present a guide to the previously published papers by us. / QC 20100810

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Le problème de la détection et de ladescription des nouveaux états quantiquesmacroscopiques, caractérisées par des propriétésexotiques et non-conventionnelles, estd’importance fondamentale dans la physiquemoderne. Ces états offrent des perspectivesfascinantes dans le domaine de traitementd’information, de simulations quantiques et derecherche des nouveaux types des matériaux.Dans ce travail de thèse nous développons unethéorie qui permet de décrire des phases non conventionnellesdans des systèmes des gazultra-froids dipolaires. Ces systèmes sontactivement étudiés expérimentalement enutilisant des atomes à grand-spins, desmolécules polaires et des excitations dipolairesdans des semi-conducteurs. Nous mettonsl'accent sur la révélation du rôle de l’interactiondipôle-dipôle à long porté.Nous considérons l’effet de rotonization dansun système de gaz des bosons dipolaires «tiltés»aux interactions faibles dans une couchehomogène. Nous prédisons l’effet derotonization pour un gaz de Bose faiblementcorrélé des excitons dipolaires dans une couchede semi-conducteur et nous calculons lediagramme de stabilité. Ensuite, nousconsidérons des superfluides d’onde-p desfermions identiques dans des réseaux 2D.Finalement, nous faisons une discussion sur unautre état superfluide intéressant des moléculespolaires fermioniques, qui devrait apparaitredans des systèmes bicouches. / The problem of revealing anddescribing novel macroscopic quantum statescharacter- ized by exotic and non-conventionalproperties is of fundamental importance formodern physics. Such states offer fascinatingprospects for potential applications in quantumin- formation processing, quantum simulation,and material research. In the present Thesis wedevelop a theory for describing nonconventionalphases of ultracold dipolar gases.The related systems of large-spin atoms, polarmolecules, and dipolar excitons in semiconductorsare actively studied in experiments.We put the main emphasis on revealing the roleof the long-range character of the dipole-dipoleinteraction.We consider the effect of rotonization for a 2Dweakly interacting gas of tilted dipolar bosonsin a homogeneous layer. We predict the effectof rotonization for a weakly correlated Bosegas of dipolar excitons in a semiconductorlayer and calculate the stability diagram. Wethen consider p-wave superfluids of identicalfermions in 2D lattices. Finally, we discussanother interesting novel superfluid offermionic polar molecules

Here I study the “plasma interactions with icy bodies in the solar system”, that is, my quest to understand the fundamental processes that govern such interactions. By using numerical modelling combined with in situ observations, one can infer the internal structure of icy bodies and their plasma environments. After a broad overview of the laws governing space plasmas a more detailed part follows. This contains the method on how to model the interaction between space plasmas and icy bodies. Numerical modelling of space plasmas is applied to the icy bodies Callisto (a satellite of Jupiter), the dwarf planet Ceres (located in the asteroid main belt) and the comet 67P/Churyumov-Gerasimenko. The time-varying magnetic field of Jupiter induces currents inside the electrically conducting moon Callisto. These create magnetic field perturbations thought to be related to conducting subsurface oceans. The flow of plasma in the vicinity of Callisto is greatly affected by these magnetic field perturbations. By using a hybrid plasma solver, the interaction has been modelled when including magnetic induction and agrees well with magnetometer data from flybys (C3 and C9) made by the Galileo spacecraft. The magnetic field configuration allows an inflow of ions onto Callisto’s surface in the central wake. Plasma that hits the surface knocks away matter (sputtering) and creates Callisto’s tenuous atmosphere. A long term study of solar wind protons as seen by the Rosetta spacecraft was conducted as the comet 67P/Churyumov-Gerasimenko approached the Sun. Here, extreme ultraviolet radiation from the Sun ionizes the neutral water of the comet’s coma. Newly produced water ions get picked up by the solar wind flow, and forces the solar wind protons to deflect due to conservation of momentum. This effect of mass-loading increases steadily as the comet draws closer to the Sun. The solar wind is deflected, but does not lose much energy. Hybrid modelling of the solar wind interaction with the coma agrees with the observations; the force acting to deflect the bulk of the solar wind plasma is greater than the force acting to slow it down. Ceres can have high outgassing of water vapour, according to observations by the Herschel Space Observatory in 2012 and 2013. There, two regions were identified as sources of water vapour. As Ceres rotates, so will the source regions. The plasma interaction close to Ceres depends greatly on the source location of water vapour, whereas far from Ceres it does not. On a global scale, Ceres has a comet-like interaction with the solar wind, where the solar wind is perturbed far downstream of Ceres. / Här studerar jag “plasmaväxelverkan med isiga kroppar i solsystemet”, det vill säga, min strävan är att förstå de grundläggande processerna som styr sådana interaktioner. Genom att använda numerisk modellering i kombination med observationer på plats vid himlakropparna kan man förstå sig på deras interna strukturer och rymdmiljöer. Efter en bred översikt över de fysiska lagar som styr ett rymdplasma följer en mer detaljerad del. Denna innehåller metoder för hur man kan modellera växelverkan mellan rymdplasma och isiga kroppar. Numerisk modellering av rymdplasma appliceras på de isiga himlakropparna Callisto (en måne kring Jupiter), dvärgplaneten Ceres (lokaliserad i asteroidbältet mellan Mars och Jupiter) och kometen 67P/Churyumov-Gerasimenko. Det tidsvarierande magnetiska fältet kring Jupiter inducerar strömmar inuti den elektriskt ledande månen Callisto. Dessa strömmar skapar magnetfältsstörningar som tros vara relaterade till ett elektriskt ledande hav under Callistos yta. Plasmaflödet i närheten av Callisto påverkas i hög grad av dessa magnetfältsstörningar. Genom att använda en hybrid-plasma-lösare har växelverkan modellerats, där effekten av magnetisk induktion har inkluderats. Resultaten stämmer väl överens med magnetfältsdata från förbiflygningarna av Callisto (C3 och C9) som gjordes av den obemannade rymdfarkosten Galileo i dess bana kring Jupiter. Den magnetiska konfigurationen som uppstår möjliggör ett inflöde av laddade joner på Callistos baksida. Plasma som träffar ytan slår bort materia och skapar Callistos tunna atmosfär. En långtidsstudie av solvindsprotoner sett från rymdfarkosten Rosetta utfördes då kometen 67P/Churyumov-Gerasimenko närmade sig solen. Ultraviolett strålning från solen joniserar det neutrala vattnet i kometens koma (kometens atmosfär). Nyligt joniserade vattenmolekyler plockas upp av solvindsflödet och tvingar solvindsprotonernas banor att böjas av, så att rörelsemängden bevaras. Denna effekt ökar stadigt då kometen närmar sig solen. Solvinden böjs av kraftigt, men förlorar inte mycket energi. Hybridmodellering av solvindens växelverkan bekräftar att kraften som verkar på solvinden till störst del får den att böjas av, medan kraften som verkar till att sänka dess fart är mycket lägre. Ceres har enligt observationer av rymdteleskopet Herschel under 2012 och 2013 haft högt utflöde av vattenånga från dess yta. Där har två regioner identifierats som källor för vattenångan. Eftersom Ceres roterar kommer källornas regioner göra det också. Plasmaväxelverkan i närheten av Ceres beror i hög grad på vattenångskällans placeringen, medan det inte gör det långt ifrån Ceres. På global nivå har Ceres en kometliknande växelverkan med solvinden, där störningar i solvinden propagerar långt nedströms från Ceres.

Small satellites are gaining popularity in a wide range of applications where attitude systems require high precision performance. One of the main sources of errors, in case of magnetic attitude control systems, is the residual magnetic moment (RMM) of the spacecraft. To keep the RMM low and stable, mitigation methods shall be applied based on the satellite’s magnetic dipole moment (MDM) characterization, which shall be measured accurately. For small satellites, the most common technique involves the generation of a field-free region for the magnetic measurements using a test bed. The test bed measurement setup is normally mechanical, where measurements from the device under test (DUT) are very tedious. Optical magnetic test beds (OMTB) are being developed for MDM characterization providing simpler set ups and faster measurements than mechanical test beds. In this work, accuracy of OMTB of Aalto University has been evaluated by measuring three permanent magnets in two configurations. The measurements show a relationship between the estimation accuracy and the DUT’s marker area seen by the camera. Moreover, it was observed that the field-free region generated by Helmholtz coil cage can generate false data points. Based on these observations, the detection of the marker’s positions have been evaluated using the view area (VA) and the pointing angle (PA). The analysis shows that there is a consistent pattern depending on the combination of the VA and PA. Hence, the method of data acquisition was improved in order to prioritize the markers which position allow better accuracy. The achieved improvement of MDM estimation results is 2 %, and the test bed’s overall error evaluated is a 13 % in MDM position estimation and 23 % in MDM magnitude estimation. The improved OMTB was used to characterize the MDM of four magnetic attitude coils of Foresail-1 satellite. The measurements results are consistent with design parameters, showing three dipole configuration in all coils with a MDM magnitude order of 10−2 A·m2. / Foresail-1

Antenna implants are used to establish a telemetry link to enable wireless data transfer, suitable for telemedicine and other medical applications. Inbody environments with water-based tissues lead to severe power absorption, making signal strength and radiation efficiency challenging yet central performance aspects of antenna implants. Fundamental performance limits exist regarding radiation efficiency; however, these limits consider theoretically ideal Hertzian dipoles. A semi-analytical model is used to evaluate the feasibility of previously determined fundamental bounds and the optimal dipole solution, both with respect to physical necessities of finite material conductivity and antenna size. This study uses a spherical model to represent a simplified in-body environment with various phantom compositions. Furthermore, the study focuses on implants operating within the Medical Implant Communication System (MICS) frequency band, but models and methods are not restricted to the considered frequency. The work contributes to the field of implantable antennas in several aspects; evaluating the feasibility of fundamental bounds, establishing more realistic performance limits, and determining the optimal dipole solution with respect to radiation efficiency. Other findings are presented in related areas, particularly concerning conductor loss and evaluation of the impedance for antennas inside a high-loss phantom. Moreover, the work presents a suggested method to measure electrically small magnetic dipole antennas. Methods and models are documented in a substantial theoretical derivation, and findings are verified using independent methods. Neglecting necessary antenna aspects like finite size and conductivity can lead to faulty conclusions on implant performance. Providing a more realistic performance target helps predict the performance of realistic antenna designs. Ultimately, increased knowledge of implanted antennas simplifies the design process to achieve high-performance implants. / Antennimplant används för att etablera en telemetrilänk som möjliggör trådlös dataöverföring, exempelvis användbart inom telemedicin och andra medicinska tillämpningar. Vattenbaserade kroppsmiljöer resulterar i kraftig absorption, vilket implicerar att signalstyrka samt strålningseffektivit blir utmanande men även centrala prestanda egenskaper för antennimplnatat. Det existerar fundamentala prestandabegränsningar för strålningseffektivitet, men dessa gränser är etablerade med hänsyn till teoretiskt ideala elementära dipoler. En semi-analytisk modell används för att utvärdera rimligheten av tidigare begränsningar samt den optimala dipolen, bägge med hänsyn till nödvändiga aspekter som ändlig konduktivitet och antennstorlek. Denna studie använder en sfärisk modell för att representera en simplifierad kroppslig miljö med olika vävnadskompositioner. Studien fokuserar på antennimplantat inom frekvensbandet dedikerat för Medical Implant Communication System (MICS) enheter, men modeller och metoder är typiskt inte begränsade inom omnämnt band. Arbetet bidrar till området för implanterbara antenner i flera aspekter; att utvärdera rimligheten av fundamentala gränser, fastställa mer realistiska prestandagränser samt bestämma den optimala dipolen med avseende på strålningseffektivitet. Andra resultat presenteras inom relaterade aspekter som metallförlust och utvärdering av en antenns last eller ingångs impedans inuti sfäriska och kroppsliga miljöer. Dessutom presenteras en metod för att mäta elektriskt små magnetiska dipoler. Metoder och modeller är dokumenterade eller demonstrerade via härledning, och centrala resultat har verifieras med oberoende metoder. Att förbise nödvändiga aspekter som ändlig storlek och konduktivitet kan leda till felaktiga slutsatser gällande prestanda. Däremot, att fastställa en mer realistisk gräns bidrar till att förutsäga prestandan i realistiska tillämpningar. I slutändan så resulterar ökad kunskap i en simplifierad designprocess som underlättar i strävan till att uppnå högpresterande antennimplantat.

Nesta dissertação é apresentado um estudo dos compostos Li1-3xMgFexPO4 através de Ressonância Magnética Nuclear (7Li e 31P), no intervalo de temperatura de 150 a 410 K. Estudos desses compostos através de técnicas de difração de elétrons e efeito Mossbauer confirmam que os íons Fe entram na rede cristalina na forma Fe3+, substituindo os íons Li+. O comportamento dos espectros de RMN, dos tempos de relaxação spin-rede e da susceptibilidade magnética dos núcleos 7Li e 31P em função da temperatura, em conjunto com medidas de condutividade iônica, indicam que, mesmo com a adição de impurezas Fe3+ na rede, os íons Li+ pouca mobilidade dentro do intervalo de temperatura utilizado. / This work reports a 7Li and 31P nuclear magnetic resonance study in the Li1-3xMgFexPO4 phases between 150 and 410 K. This study, complementary to those made using Mössbauer and magnetic neutron diffraction experiments, confirms that the Fe3+ ions enter as in the lattice, and that they enter substituting Li ions. The behavior of the 7Li e 31P nuclear magnetic resonance spectra, together with ionic conductivity measurements, show that no Li mobility occurs in temperature range studied even with the addition of the Fe impurity.

Nesta dissertação é apresentado um estudo dos compostos Li1-3xMgFexPO4 através de Ressonância Magnética Nuclear (7Li e 31P), no intervalo de temperatura de 150 a 410 K. Estudos desses compostos através de técnicas de difração de elétrons e efeito Mossbauer confirmam que os íons Fe entram na rede cristalina na forma Fe3+, substituindo os íons Li+. O comportamento dos espectros de RMN, dos tempos de relaxação spin-rede e da susceptibilidade magnética dos núcleos 7Li e 31P em função da temperatura, em conjunto com medidas de condutividade iônica, indicam que, mesmo com a adição de impurezas Fe3+ na rede, os íons Li+ pouca mobilidade dentro do intervalo de temperatura utilizado. / This work reports a 7Li and 31P nuclear magnetic resonance study in the Li1-3xMgFexPO4 phases between 150 and 410 K. This study, complementary to those made using Mössbauer and magnetic neutron diffraction experiments, confirms that the Fe3+ ions enter as in the lattice, and that they enter substituting Li ions. The behavior of the 7Li e 31P nuclear magnetic resonance spectra, together with ionic conductivity measurements, show that no Li mobility occurs in temperature range studied even with the addition of the Fe impurity.