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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Fermions and Bosons on an Atom Chip

Extavour, Marcius H. T. 18 February 2010 (has links)
Ultra-cold dilute gases of neutral atoms are attractive candidates for creating controlled mesoscopic quantum systems. In particular, quantum degenerate gases of bosonic and fermionic atoms can be used to model the correlated many-body behaviour of Bose and Fermi condensed matter systems, and to study matter wave interference and coherence. This thesis describes the experimental realization and manipulation of Bose-Einstein condensates (BECs) of 87Rb and degenerate Fermi gases (DFGs) of 40K using static and dynamic magnetic atom chip traps. Atom chips are versatile modern tools used to manipulate atomic gases. The chips consist of micrometre-scale conductors supported by a planar insulating substrate, and can be used to create confining potentials for neutral atoms tens or hundreds of micrometres from the chip surface. We demonstrate for the first time that a DFG can be produced via sympathetic cooling with a BEC using a simple single-vacuum-chamber apparatus. The large 40K-87Rb collision rate afforded by the strongly confining atom chip potential permits rapid cooling of 40K to quantum degeneracy via sympathetic cooling with 87Rb. By studying 40K-87Rb cross-thermalization as a function of temperature, we observe the Ramsauer-Townsend reduction in the 40K-87Rb elastic scattering cross-section. We achieve DFG temperatures as low as T = 0.1TF , and observe Fermi pressure in the time-of-flight expansion of the gas. This thesis also describes the radio-frequency (RF) manipulation of trapped atoms to create dressed state double-well potentials for BEC and DFG.We demonstrate for the first time that RF-dressed potentials are species-selective, permitting the formation of simultaneous 87Rb double-well and 40K single-well potentials using a 40K-87Rb mixture. We also develop tools to measure fluctuations of the relative atom number and relative phase of a dynamically split 87Rb BEC. In particular, we observe atom number fluctuations at the shot-noise level using time-of-flight absorption imaging. These measurement tools lay the foundation for future investigations of number squeezing and matter wave coherence in BEC and DFG systems.
82

Dinâmica de dois condensados de Bose-Einstein - Tratamento de campo médio / Dynamics of two Bose-Einstein condensates: mean-field treatment

Renata Benedicto Prandini 01 October 2002 (has links)
Investigamos o sistema formado por dois condensados aprisionados em estados hiperfinos diferentes do Rubídio, num potencial em forma de charuto, ou seja, num sistema físico real e quase-unidimensional. É investigada a dependência das soluções das equações de Gross-Pitaevski com a separação entre as armadilhas, bem como com o parâmetro de acoplamento de Josephson, para três valores diferentes do número total de átomos aprisionados. Para alguns conjuntos de parâmetros constatamos a existência de estados metaestáveis. O observável que escolhemos para caracterizar tal sistema físico foi a separação média entre os pacotes, pois os dois ramos de soluções encontramos correspondem a soluções mais juntas ou mais separadas espacialmente. / We study the system formed by two coupled condensates of different Rubidium hyperfine states trapped in a cigar shaped potential, that is, a real quasi one-dimensional system. The dependency of the solution of the Gross-Pitaevski equations is investigated as a function of trap displacement and Josephson coupling parameter for three different values of the total trapped atoms number. For some sets of parameters we report the existence of metastable states. The observable we chose to characterize this system was the mean separation between the packages, because we found two branches which correspond to closer or more separated solutions.
83

Control of photoassociation of atomic Bose-Einstein condensates by laser field configuration / Contrôle de la photo-association de condensats de Bose-Einstein atomiques par configuration de champs laser

Gevorgyan, Mariam 11 October 2016 (has links)
Dans ce travail, nous montrons qu'il est possible d'effectuer un passage adiabatique efficace dans un système quantique non-linéaire quadratique à deux états décrivant la formation de molécules faiblement liées dans les condensats atomiques de Bose-Einstein par la photo-association par champs laser.Un transfert adiabatique efficace est également possible si on prend en compte les non-linéarités de troisième ordre décrivant les collisions élastiques atome-atome, atome-molécule et moléculaire-molécule.Le transfert est obtenu en choisissant un désaccord approprié calculé en résolvant le problème inverse.Nous montrons également que l'on peut effectuerun suivi Raman stimulé exact dans un système non-linéaire quantique à trois états.Dans le passage d'atomes libres à l'état moléculaire stable, les pertes irréversibles de l'état moléculaire intermédiaire faiblement lié peuvent être évitées par un schéma à trois états en deux couleurs dans le cas avec résonances à un ou deux photons.Ceci est obtenu par une technique de suivi exacte.Nous avons également étudié des modèles linéaires à deux états bi-confluents de Heun, dépendant du temps, avec des solutions en termes de combinaisons linéaires d'un nombre fini de fonctions Hermite d'ordre non entier.Nous avons présenté un modèle dont la solution implique seulement deux fonctions Hermite. Il s'agit d'une configuration de champ avec croisement par résonance donnée par une fréquence Rabi exponentiellement divergente et un désaccord qui commence à partir de la résonance exacte et diverge exponentiellement à l'infini. Le modèle prend en compte les pertes irréversibles du second état. / In this work we show that it is to perform an efficient adiabatic passage in a basic quadratic-nonlinear quantum two-state system describing weakly bound molecule formation in atomic Bose-Einstein condensates through photoassociation by laser fields. An efficient adiabatic transfer is also possible if the third-order nonlinearities describing the atom-atom, atom-molecule, and molecule-molecule elastic scattering are taken into account. The transfer is achieved by choosing a proper detuning derived by solving the inverse problem.We also show that one can perform a stimulated Raman exact tracking in a quadratic-nonlinear quantum three-state system.The irreversible losses from the intermediate weakly bound molecular state in a passage of free atoms to the stable molecular state can be avoided by a two-colour three-state scheme in the case of one- and two-photon resonances for the associating laser fields.This is achieved by an exact tracking technique.We also studied the linear time-dependent two-state bi-confluent Heun models with solutions in terms of linear combinations of a finite numberof the Hermite functions of non-integer order.We have presented a model the solution for which involves just two Hermite functions.This is a resonance-crossing field configuration given by an exponentially diverging Rabi frequency and a detuning that starts from the exact resonance and exponentially diverges at the infinity. The model takes into account the irreversible losses from the second state.
84

Mixtures of superfluids / Mélanges de superfluides

Delehaye, Marion 08 April 2016 (has links)
Les atomes froids sont des outils uniques pour sonder la physique de la matière quantique. Hautement contrôlables, les gaz de Bose et de Fermi ultrafroids sont des systèmes idéaux pour la simulation quantique et pour explorer des manifestations spectaculaires des effets quantiques, comme la superfluidité. Avec des gaz froids de 6Li et de 7Li, nous avons produit le premier mélange de superfluides bosonique-fermionique, et étudié ses propriétés en initiant un contre-flot entre les nuages de Bose et de Fermi (mode dipolaire). La vitesse critique de superfluidité a été mesurée dans le crossover BEC-BCS et elle est trouvée proche de la vitesse du son dans le gaz de Fermi. Nous comparons nos mesures avec des prédictions théoriques récentes. En élevant la température du mélange, nous avons aussi observé une synchronisation inattendue entre les mouvements des deux nuages, interprétée comme un effet Zénon induit par la dissipation. Finalement, ce mélange de bosons et de fermions offre la possibilité unique de créer un piège homogène pour le gaz de Fermi. En ajustant finement les interactions, nous proposons d’utiliser la répulsion entre les bosons et les fermions pour compenser la courbure du piège harmonique pour les fermions. Pour des fermions présentant une polarisation de spin, nous prédisons théoriquement l’existence d’un superfluide avec une structure en “coquille” et fournissons les premières indications expérimentales de l’observation de ce superfluide topologiquement original. / Ultracold atoms are unique tools to probe the physics of quantum matter. Indeed, the high degree of tunability of ultracold Bose and Fermi gases makes them ideal systems for quantum simulation and for exploring macroscopic manifestations of quantum effects, such as superfluidity. In this work, we have realized the first Bose-Fermi superfluid mixture, with ultracold gases of 6Li and 7Li. The properties of the mixture are investigated by initiating a Bose-Fermi counterflow through their dipole modes. The superfluid critical velocity is measured in the BEC-BCS crossover, and is found close to the sound velocity of the Fermi gas near unitarity. We compare our findings to recent theoretical predictions. Raising the temperature of the mixture, we observe an unexpected synchronization of the motion of the two clouds, interpreted with a Zeno-like model induced by dissipation. Finally, this Bose-Fermi mixture offers the unique possibility to create a homogeneoustrap for the Fermi gas. By a fine tuning of the interactions, we propose to use the Bose-Fermi repulsion to compensate the curvature of the harmonic trap for fermions. For a spin-polarized Fermi gas in such a trap, we theoretically predict the existence of a superfluid with a shell structure and we provide first experimental evidence for this topologically new superfluid.
85

Sobre a dinâmica das colisões atômicas frias controladas em redes ópticas / On the dynamic of the cold atomic controlled collisions in optical lattices

Farias, Reginaldo de Jesus Costa, 1978- 18 August 2018 (has links)
Orientador: Marcos César de Oliveira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-18T12:10:11Z (GMT). No. of bitstreams: 1 Farias_ReginaldodeJesusCosta_D.pdf: 4228413 bytes, checksum: 9e7ff892eed5441839ee091ddb080501 (MD5) Previous issue date: 2011 / Resumo: Partindo de uma derivação matemática do modelo de Bose-Hubbard, desenvolvemos os cálculo para o emaranhamento bi e multipartido, através da transição Isolante de Mott-superuida, entre os modos de uma rede óptica para as situações mais simples de dois, três e quatro átomos (N) depositados nestas com igual número de sítios M, ocasionando um fator de preenchimento ? = N=M unitário. Apresentamos uma investigação sobre o controle da dinâmica de um condensado de Bose-Einstein aprisionado em um poço duplo através da ação de um potencial externo dependente do tempo. Apresentamos também uma investigação preliminar de codificação e operações quânticas embasadas em colisões controladas entre átomos em múltiplos poços / Abstract: Starting from a mathematical derivation of the Bose-Hubbard Model (BHM) we analyze the developing of bipartite and multipartite entanglement through the Mott insulator-superuid quantum phase transition, among the modes of an optical lattice to the simplest situations of two, three and four atoms (N) deposited in such optical lattice with equal number of sites (M), where a filling factor ? = N=M = 1 per lattice site is considered. We present an investigation about the controlled dynamic of a Bose-Einstein condensate in a double well driven by an external time dependent potential. Beyond we present some preliminar notes on codi cations and quantum operations in cold controlled collisions among atoms in multiples wells / Doutorado / Física da Matéria Condensada / Doutor em Ciências
86

Engineered atomic states for precision interferometry / Ingénierie d’états atomiques pour l’interférométrie de précision

Corgier, Robin 02 July 2019 (has links)
La physique moderne repose sur deux théories fondamentales distinctes, la relativité générale et la mécanique quantique. Toutes les deux décrivent d’une part les phénomènes macroscopiques et cosmologiques tels que les ondes gravitationnelles et les trous noirs et d’autre part les phénomènes microscopiques comme la superfluidité ou le spin des particules. L’unification de ces deux théories reste, jusqu’à présent, un problème non résolu. Il est intéressant de noter que les différentes théories de gravité quantique prédisent une violation des principes de la relativité générale à différents niveaux.Il est donc hautement intéressant de détecter les violations de ces principes et de déterminer à quel niveau elles se produisent.De récentes propositions pour effectuer des tests du principe d’ équivalence d’Einstein suggèrent une amélioration spectaculaire des performances en utilisant des capteurs atomiques `a ondes de matière.Dans ce contexte, il est nécessaire de concevoir des états d’entrée de l’interferomètre avec des conditions initiales bien définies. Un test de pointe de l’universalité de la chute libre (Universality of FreeFall en anglais (UFF) ) nécessiterait, par exemple,un contrôle des positions et des vitesses avec une précision de l’ordre de 1 μm et 1 μm.s⁻¹ , respectivement.De plus, les systématiques liées à la taille du paquet d’ondes limitent le taux d’expansion maximum possible à 100 μm.s⁻¹. La création initiale des états d’entrée de l’interféromètre doit être assez rapide,de l’ordre de quelques centaines de ms au maximum,pour que le temps de cycle de l’expérience soit pertinent d’un point de vue métrologique. Dans cette thèse j’ai développé des séquences optimisées s’appuyant sur l’excitation du centre de masse et de la taille d’un ou plusieurs ensembles d’atomes refroidis ainsi que dégénérés. Certaines séquences proposé dans cette thèse ont déjà été implémenté dans des expériences augmentant de manière significative le contrôle des ensembles atomiques. / Modern physics relies on two distinct fundamental theories, General Relativity and Quantum Mechanics. Both describe on one hand macroscopic and cosmological phenomena such as gravitational waves and black holes and on the other hand microscopic phenomena as superfluidity or the spin of particles. The unification of these two theories remains, so far, an unsolved problem. Interestingly, candidate Quantum Gravity theories predict a violation of the principles of General Relativity at different levels. It is, therefore, of a timely interest to detect violations of these principles and determine at which level they occur. Recent proposals to perform Einstein Equivalence Principle tests suggest a dramatic performance improvement using matter-wave atomic sensors. In this context, the design of the input states with well defined initial conditions is required. A state-of-the-art test of the universality of free fall (UFF) would, for example, require a control of positions and velocities at the level of 1 µm and 1 µm.s⁻¹, respectively. Moreover, sizerelated systematics constrain the maximum expansion rate possible to the 100 µm.s⁻¹level. This initial engineering of the input states has to be quite fast, of the order of few hundred ms at maximum, for the experiment’s duty cycle to be metrologically-relevant. In this thesis I developed optimized sequences based on the excitation of the center of mass and the size excitation of one or two cooled atomic sample as well as degenerated gases. Some sequences proposed in this thesis have already been implemented in experiments and significantly increase the control of atomic ensembles.
87

Bose-Einstein Condensates in Synthetic Gauge Fields and Spaces: Quantum Transport, Dynamics, and Topological States

Chuan-Hsun Li (7046690) 14 August 2019 (has links)
<p>Bose-Einstein condensates (BECs) in light-induced synthetic gauge fields and spaces can provide a highly-tunable platform for quantum simulations. Chapter 1 presents a short introduction to the concepts of BECs and our BEC machine. Chapter 2 introduces some basic ideas of how to use light-matter interactions to create synthetic gauge fields and spaces for neutral atoms. Three main research topics of the thesis are summarized below.</p> <p>Chapter 3: Recently, using bosonic quasiparticles (including their condensates) as spin carriers in spintronics has become promising for coherent spin transport over macroscopic distances. However, understanding the effects of spin-orbit (SO) coupling and many-body interactions on such a spin transport is barely explored. We study the effects of synthetic SO coupling (which can be turned on and off, not allowed in usual materials) and atomic interactions on the spin transport in an atomic BEC.</p> <p>Chapter 4: Interplay between matter and fields in physical spaces with nontrivial geometries can lead to phenomena unattainable in planar spaces. However, realizing such spaces is often impeded by experimental challenges. We synthesize real and curved synthetic dimensions into a Hall cylinder for a BEC, which develops symmetry-protected topological states absent in the planar counterpart. Our work opens the door to engineering synthetic gauge fields in spaces with a wide range of geometries and observing novel phenomena inherent to such spaces.</p> <p>Chapter 5: Rotational properties of a BEC are important to study its superfluidity. Recent studies have found that SO coupling can change a BEC's rotational and superfluid properties, but this topic is barely explored experimentally. We study rotational dynamics of a SO-coupled BEC in an effective rotating frame induced by a synthetic magnetic field. Our work may allow for studying how SO coupling modify a BEC's rotational and superfluid properties.</p> <p>Chapter 6 presents some possible future directions.</p>
88

Matter wave interferometry in microgravity

Krutzik, Markus 20 October 2014 (has links)
Quantensensoren auf Basis ultra-kalter Atome sind gegenwärtig auf dem Weg ihre klassischen Pendants als Messintrumente sowohl in Präzision als auch in Genauigkeit zu überholen, obwohl ihr Potential noch immer nicht vollständig ausgeschöpft ist. Die Anwendung von Quantensensortechnologie wie Materiewelleninterferometern im Weltraum wird ihre Sensitivität weiter steigen lassen, sodass sie potentiell die genauesten erdbasierten Systeme um mehrere Grössenordnungen übertreffen könnten. Mikrogravitationsplattformen wie Falltürme, Parabelflugzeuge und Höhenforschungsraketen stellen exzellente Testumgebungen für zukünftge atominterferometrische Experimente im Weltraum dar. Andererseits erfordert ihre Nutzung die Entwicklung von Schlüsseltechnologien, die hohe Standards in Bezug auf mechanische und thermische Robustheit, Autonomie, Miniaturisierung und Redundanz erfüllen müssen. In der vorliegenden Arbeit wurden erste Interferometrieexperimente mit degenerieten Quantengasen in Schwerelosigkeit im Rahmen des QUANTUS Projektes durchgeführt. In mehr als 250 Freifall-Experimenten am Bremer Fallturm konnte die Präparation, freie Entwicklung und Phasenkohärenz eines Rubidium Bose- Einstein Kondensates (BEC) auf makroskopischen Zeitskalen von bis zu 2 s untersucht werden. Dazu wurde ein BEC-Interferometer mittels Bragg-Strahlteilern in einen Atomchip-basierten Aufbau implementiert. In Kombination mit dem Verfahren der Delta-Kick Kühlung (DKC) konnte die Expansionsrate der Kondensate weiter reduziert werden, was zur Beobachtung von effektiven Temperaturen im Bereich von 1 nK führte. In einem Interferometer mit asymetrischer Mach-Zehnder Geometrie konnten Interferenzstreifen mit hohem Kontrast bis zu einer Verweildauer von 2T = 677 ms untersucht werden. / State-of-the-art cold atomic quantum sensors are currently about to outpace their classical counterparts in precision and accuracy, but are still not exploiting their full potential. Utilizing quantum-enhanced sensor technology such as matter wave interferometers in the unique environment of microgravity will tremendously increase their sensitivity, ultimately outperforming the most accurate groundbased systems by several orders of magnitude. Microgravity platforms such as drop towers, zero-g airplanes and sounding rockets are excellent testbeds for advanced interferometry experiments with quantum gases in space. In return, they impose demanding requirements on the payload key technologies in terms of mechanical and thermal robustness, remote control, miniaturization and redundancy. In this work, first interferometry experiments with degenerate quantum gases in zero-g environment have been performed within the QUANTUS project. In more than 250 free fall experiments operated at the drop tower in Bremen, preparation, free evolution and phase coherence of a rubidium Bose-Einstein condensate (BEC) on macroscopic timescales of up to 2 s have been explored. To this end, a BEC interferometer using first-order Bragg diffraction was implemented in an atomchip based setup. Combined with delta-kick cooling (DKC) techniques to further slow down the expansion of the atomic cloud, effective temperatures of about 1 nK have been reached. With an asymmetrical Mach-Zehnder geometry, high-contrast interferometric fringes were observed up to a total time in the interferometer of 2T = 677 ms.
89

Physics of quantum fluids in two-dimensional topological systems / Physique des fluides quantiques dans des systèmes topologiques bidimensionnels

Bleu, Olivier 27 September 2018 (has links)
Cette thèse est consacrée à la description de la physique à une particule ainsi qu'à celle de fluides quantiques bosoniques dans des systèmes topologiques. Les deux premiers chapitres sont introductifs. Dans le premier, nous introduisons des éléments de théorie des bandes et les quantités géométriques et topologiques associées : tenseur métrique quantique, courbure de Berry, nombre de Chern. Nous discutons différents modèles et réalisations expérimentales donnant lieu à des effets topologiques. Dans le second chapitre, nous introduisons les condensats de Bose-Einstein ainsi que les excitons-polaritons de cavité.La première partie des résultats originaux discute des phénomènes topologiques à une particule dans des réseaux en nid d'abeilles. Cela permet de comparer deux modèles théoriques qui mènent à l'effet Hall quantique anormal pour les électrons et les photons dû à la présence d'un couplage spin-orbite et d'un champ Zeeman. Nous étudions aussi l'effet Hall quantique de vallée photonique à l'interface entre deux réseaux de cavités avec potentiels alternés opposés.Dans une seconde partie, nous discutons de nouveaux effets qui émergent due à la présence d'un fluide quantique interagissant décrit par l’équation de Gross-Pitaevskii dans ces systèmes. Premièrement, il est montré que les interactions spin anisotropes donnent lieu à des transitions topologiques gouvernées par la densité de particules pour les excitations élémentaires d’un condensat spineur d’exciton-polaritons.Ensuite, nous montrons que les tourbillons quantifiés d'un condensat scalaire dans un système avec effet Hall quantique de vallée, manifestent une propagation chirale le long de l'interface contrairement aux paquets d'ondes linéaires. La direction de propagation de ces derniers est donnée par leur sens de rotation donnant lieu à un transport de pseudospin de vallée protégé topologiquement, analogue à l’effet Hall quantique de spin.Enfin, revenant aux effets géométriques linéaires, nous nous sommes concentrés sur l’effet Hall anormal. Dans ce contexte, nous présentons une correction non-adiabatique aux équations semi-classiques décrivant le mouvement d’un paquet d’ondes qui s’exprime en termes du tenseur géométrique quantique. Nous proposons un protocole expérimental pour mesurer cette quantité dans des systèmes photonique radiatifs. / This thesis is dedicated to the description of both single-particle and bosonic quantum fluid Physics in topological systems. After introductory chapters on these subjects, I first discuss single-particle topological phenomena in honeycomb lattices. This allows to compare two theoretical models leading to quantum anomalous Hall effect for electrons and photons and to discuss the photonic quantum valley Hall effect at the interface between opposite staggered cavity lattices.In a second part, I present some phenomena which emerge due to the interplay of the linear topological effects with the presence of interacting bosonic quantum fluid described by mean-field Gross-Pitaevskii equation. First, I show that the spin-anisotropic interactions lead to density-driven topological transitions for elementary excitations of a condensate loaded in the polariton quantum anomalous Hall model (thermal equilibrium and out-of-equilibrium quasi-resonant excitation configurations). Then, I show that the vortex excitations of a scalar condensate in a quantum valley Hall system, contrary to linear wavepackets, can exhibit a robust chiral propagation along the interface, with direction given by their winding in real space, leading to an analog of quantum spin Hall effect for these non-linear excitations. Finally, coming back to linear geometrical effects, I will focus on the anomalous Hall effect exhibited by an accelerated wavepacket in a two-band system. In this context, I present a non-adiabatic correction to the known semiclassical equations of motion which can be expressed in terms of the quantum geometric tensor elements. We also propose a protocol to directly measure the tensor components in radiative photonic systems.
90

Probing Dynamics and Correlations in Cold-Atom Quantum Simulators

Geier, Kevin Thomas 21 July 2022 (has links)
Cold-atom quantum simulators offer unique possibilities to prepare, manipulate, and probe quantum many-body systems. However, despite the high level of control in modern experiments, not all observables of interest are easily accessible. This thesis aims at establishing protocols to measure currently elusive static and dynamic properties of quantum systems. The experimental feasibility of these schemes is illustrated by means of numerical simulations for relevant applications in many-body physics and quantum simulation. In particular, we introduce a general method for measuring dynamical correlations based on non-Hermitian linear response. This enables unbiased tests of the famous fluctuation-dissipation relation as a probe of thermalization in isolated quantum systems. Furthermore, we develop ancilla-based techniques for the measurement of currents and current correlations, permitting the characterization of strongly correlated quantum matter. Another application is geared towards revealing signatures of supersolidity in spin-orbit-coupled Bose gases by exciting the relevant Goldstone modes. Finally, we explore a scenario for quantum-simulating post-inflationary reheating dynamics by parametrically driving a Bose gas into the regime of universal far-from-equilibrium dynamics. The presented protocols also apply to other analog quantum simulation platforms and thus open up promising applications in the field of quantum science and technology. / I simulatori quantistici ad atomi freddi offrono possibilità uniche per preparare, manipolare e sondare sistemi quantistici a molti corpi. Tuttavia, nonostante l'alto livello di controllo raggiunto negli esperimenti moderni, non tutte le osservabili di interesse sono facilmente accessibili. Lo scopo di questa tesi è quello di stabilire protocolli per misurare delle proprietà statiche e dinamiche dei sistemi quantistici attualmente inaccessibili. La fattibilità sperimentale di questi schemi è illustrata mediante simulazioni numeriche per applicazioni rilevanti nella fisica a molti corpi e nella simulazione quantistica. In particolare, introduciamo un metodo generale per misurare le correlazioni dinamiche basato su una risposta lineare non hermitiana. Ciò consente test imparziali della famosa relazione fluttuazione-dissipazione come sonda di termalizzazione in sistemi quantistici isolati. Inoltre, sviluppiamo tecniche basate su ancilla per la misura di correnti e correlazioni di corrente, consentendo la caratterizzazione della materia quantistica fortemente correlata. Un'altra applicazione è orientata a rivelare l'impronta della supersolidità nei gas Bose con accoppiamento spin-orbita eccitando il corrispondente modo di Goldstone. Infine, esploriamo uno scenario per la simulazione quantistica della dinamica di riscaldamento post-inflazione modulando parametricamente un gas Bose e portandolo nel regime della dinamica universale lontana dall'equilibrio. I protocolli presentati si applicano anche ad altre piattaforme di simulazione quantistica analogica e aprono quindi applicazioni promettenti nel campo della scienza e della tecnologia quantistica. / Quantensimulatoren auf Basis ultrakalter Atome eröffnen einzigartige Möglichkeiten zur Präparation, Manipulation und Untersuchung von Quanten-Vielteilchen-Systemen. Trotz des hohen Maßes an Kontrolle in modernen Experimenten sind jedoch nicht alle interessanten Observablen auf einfache Weise zugänglich. Ziel dieser Arbeit ist es, Protokolle zur Messung aktuell nur schwer erfassbarer statischer und dynamischer Eigenschaften von Quantensystemen zu etablieren. Die experimentelle Realisierbarkeit dieser Verfahren wird durch numerische Simulationen anhand relevanter Anwendungen in der Vielteilchenphysik und Quantensimulation veranschaulicht. Insbesondere wird eine allgemeine Methode zur Messung dynamischer Korrelationen basierend auf der linearen Antwort auf nicht-hermitesche Störungen vorgestellt. Diese ermöglicht unabhängige Tests des berühmten Fluktuations-Dissipations-Theorems als Indikator der Thermalisierung isolierter Quantensysteme. Darüber hinaus werden Verfahren zur Messung von Strömen und Strom-Korrelationen mittels Kopplung an einen Hilfszustand entwickelt, welche die Charakterisierung stark korrelierter Quantenmaterie erlauben. Eine weitere Anwendung zielt auf die Enthüllung spezifischer Merkmale von Supersolidität in Spin-Bahn-gekoppelten Bose-Einstein-Kondensaten ab, indem die relevanten Goldstone-Moden angeregt werden. Schließlich wird ein Szenario zur Quantensimulation post-inflationärer Thermalisierungsdynamik durch die parametrische Anregung eines Bose-Gases in das Regime universeller Dynamik fern des Gleichgewichts erschlossen. Die dargestellten Protokolle lassen sich auch auf andere Plattformen für analoge Quantensimulation übertragen und eröffnen damit vielversprechende Anwendungen auf dem Gebiet der Quantentechnologie.

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