The search for quantum spin liquids (QSLs) introduces some of the most challenging and interesting problems in contemporary physics. The recently discovered iridate Cu2IrO3,which contains a honeycomb lattice of Ir4+ions with effective spin 1/2 coupled by frustrated Ising interactions, presents itself as a promising candidate for a Kitaev QSL. In this study, we use nuclear magnetic resonance (NMR), a spectroscopic technique based on the energy levels of nuclear spin states, to probe the intrinsic spin excitations of Cu2IrO3. By measuring the NMR frequency shift of 63Cu from 4.2 K to 298 K,we demonstrate that its spin susceptibility χ spin behaves nearly identically to its parent compound Na2IrO3, without showing evidence of magnetic ordering at low temperatures. We showed that the upturn of bulk susceptibility χ below T=50 K is due to the contribution of defect spins. The hyperfine coupling constant Ahf between Cu and Ir4+was also estimated by comparing the Knight shift 63K to χ / Thesis / Master of Science (MSc)

In this dissertation, two exactly solvable models from the Kitaev class [Ann. Phys. 321, 2 (2006)] of exactly solvable models are analysed. In the second chapter, Kitaev models and their generic properties are reviewed. Majorana fermions are introduced and discussed. Then their relationship with the solution of Kitaev models are discussed which involves the emergence of a Z₂ gauge symmetry and anyonic particles of both Abelian and non-Abelian varieties. The third chapter, which is based on the research article [Phys. Rev. B (Rapid Comm.) 83, (2011)], examines the Kitaev model on the kagome lattice. A rich phase diagram of this model is found to include a topological (gapped) chiral spin liquid with gapless chiral edge states, and a gapless chiral spin liquid phase with a spin Fermi surface. The ground state of the current model contains an odd number of electrons per unit cell which qualitatively distinguishes it from previously studied exactly solvable models with a spin Fermi surface. Moreover, it is shown that the spin Fermi surface is stable against weak perturbations. The fourth chapter is based on the article [Phys. Rev. B 84,(2011)] and analyses a disordered generalisation of the Yao-Kivelson [Phys. Rev. Lett. 99,247203 (2007)] chiral spin-liquid on the decorated honeycomb lattice. The model is generalised by the inclusion of random exchange couplings. The phase diagram was determined and it is found that disorder enlarges the region of the topological non-Abelian phase with finite Chern number. A study of the energy level statistics as a function of disorder and other parameters in the Hamiltonian show that the phase transition between the non-Abelian and Abelian phases of the model at large disorder can be associated with pair annihilation of extended states at zero energy. Analogies to integer quantum Hall systems, topological Anderson insulators, and disordered topological Chern insulators are discussed. / text

Neste trabalho investigamos a fusão entre estados ligados de Majorana em nanoestruturas compostas por um ponto quântico conectado a contatos metálicos e acoplado lateralmente a dois fios quânticos supercondutores que sustentam modos de Majorana em suas pontas. Modelando cada fio quântico por uma cadeia de Kitaev, nós adotamos duas abordagens: inicialmente usando as funções de Green do ponto obtidas através do método recursivo calculamos a condutância e a densidade local de estados (LDOS), posteriormente diagonalizamos o sistema no formalismo de Bogoliubov-de Gennes (BdG) e obtemos o espectro completo dos autoestados. Como descrito em (1), o LDOS do ponto quântico acoplado a uma única cadeia de Kitaev mostra claramente o vazamento do modo de Majorana inicialmente presente na ponta da cadeia para o ponto quântico, onde este modo surge fixo na energia de Fermi dos contatos metálicos (εƒ). A condutância de dois terminais medida através do ponto mostra uma assinatura dos estados de Majorana neste sistema, uma ressonância fixa mesmo quando o nível do ponto está vazio ou não. Interessante ressaltar que mesmo na presença de interações no ponto essa assinatura de Majorana é válida como mostrado em (2). Motivados por estes resultados anteriores estamos particularmente interessados em investigar a hibridização (aqui denominada de fusão) entre dois modos de Majorana resultando em um modo fermiônicos ordinário dentro do ponto quântico. Nossos resultados demonstram que controlando a diferença de fase supercondutora entre os fios e a voltagem de gate do ponto quântico somos capazes de controlar a emergência e fusão dos modos de Majorana. Além disso nós reforçamos a proposta de se utilizar o efeito Josephson a.c. de período 4π para identificar os modos de Majorana pela reprodução dos resultados obtidos por (3). / In this work we investigate the fusion between Majorana bound states in nanostructures composed of a quantum dot connected to source and drain leads and side coupled to two topological superconducting nanowires sustaining Majorana end modes. Modeling the nanowire via a Kitaev chain, we have used two approaches: first using a recursive Greensfunction approach we calculate the conductance and local density of states (LDOS) and then by the diagonalization using the Bogoliubov-de Gennes (BdG) formalism we obtain the full spectrum of eigenstates. As described in (1) the LDOS of quantum dot coupled to a single wire clearly shows a leakage of the Majorana end mode from the wire into the dot, where it emerges as a unique dot level pinned to the Fermi energy of the leads (εƒ). The calculated two-terminal conductance through the dot displays an unambiguous signature of the Majorana bound states, i. e., a pinned resonance occurring even when the dot level is far above εƒ . Interestingly this Majorana signature remains even in the presence of interactions within the dot as showed in (2). Motivated by these earlier results we are particularly interested to investigate the fusion of Majonana end modes into ordinary fermionic modes within the dot. Our results demonstrate that by tuning the superconducting phase difference between the wires and the quantum-dot gate voltage we are able to control the emergence and splitting of Majorana modes. Furthermore we reinforce the proposal of using the 4π periodic a.c Josephson effect to identify Majorana modes by reproducing the results obtained by (3).

Neste trabalho investigamos a fusão entre estados ligados de Majorana em nanoestruturas compostas por um ponto quântico conectado a contatos metálicos e acoplado lateralmente a dois fios quânticos supercondutores que sustentam modos de Majorana em suas pontas. Modelando cada fio quântico por uma cadeia de Kitaev, nós adotamos duas abordagens: inicialmente usando as funções de Green do ponto obtidas através do método recursivo calculamos a condutância e a densidade local de estados (LDOS), posteriormente diagonalizamos o sistema no formalismo de Bogoliubov-de Gennes (BdG) e obtemos o espectro completo dos autoestados. Como descrito em (1), o LDOS do ponto quântico acoplado a uma única cadeia de Kitaev mostra claramente o vazamento do modo de Majorana inicialmente presente na ponta da cadeia para o ponto quântico, onde este modo surge fixo na energia de Fermi dos contatos metálicos (εƒ). A condutância de dois terminais medida através do ponto mostra uma assinatura dos estados de Majorana neste sistema, uma ressonância fixa mesmo quando o nível do ponto está vazio ou não. Interessante ressaltar que mesmo na presença de interações no ponto essa assinatura de Majorana é válida como mostrado em (2). Motivados por estes resultados anteriores estamos particularmente interessados em investigar a hibridização (aqui denominada de fusão) entre dois modos de Majorana resultando em um modo fermiônicos ordinário dentro do ponto quântico. Nossos resultados demonstram que controlando a diferença de fase supercondutora entre os fios e a voltagem de gate do ponto quântico somos capazes de controlar a emergência e fusão dos modos de Majorana. Além disso nós reforçamos a proposta de se utilizar o efeito Josephson a.c. de período 4π para identificar os modos de Majorana pela reprodução dos resultados obtidos por (3). / In this work we investigate the fusion between Majorana bound states in nanostructures composed of a quantum dot connected to source and drain leads and side coupled to two topological superconducting nanowires sustaining Majorana end modes. Modeling the nanowire via a Kitaev chain, we have used two approaches: first using a recursive Greensfunction approach we calculate the conductance and local density of states (LDOS) and then by the diagonalization using the Bogoliubov-de Gennes (BdG) formalism we obtain the full spectrum of eigenstates. As described in (1) the LDOS of quantum dot coupled to a single wire clearly shows a leakage of the Majorana end mode from the wire into the dot, where it emerges as a unique dot level pinned to the Fermi energy of the leads (εƒ). The calculated two-terminal conductance through the dot displays an unambiguous signature of the Majorana bound states, i. e., a pinned resonance occurring even when the dot level is far above εƒ . Interestingly this Majorana signature remains even in the presence of interactions within the dot as showed in (2). Motivated by these earlier results we are particularly interested to investigate the fusion of Majonana end modes into ordinary fermionic modes within the dot. Our results demonstrate that by tuning the superconducting phase difference between the wires and the quantum-dot gate voltage we are able to control the emergence and splitting of Majorana modes. Furthermore we reinforce the proposal of using the 4π periodic a.c Josephson effect to identify Majorana modes by reproducing the results obtained by (3).

We investigate the properties of the Kitaev honeycomb model with both site dilution and exchange randomness. Embarking on this work, we review disorder in some strongly correlated electron systems, including spin-½ and spin-1 Heisenberg antiferromagnetic chains, two dimensional Heisenberg antiferromagnets, the cuprates and graphene. We outline some aspects of resonating valence bond phases, valence bond solids, spin liquids and quantum computation that are pertinent to an understanding of the Kitaev model. The properties of the Kitaev model without disorder are discussed and it is found to be a critical spin liquid, with algebraic correlations in two spin operators sigma^{alpha}_{i}sigma^{alpha}_{j}, where i and j,/em> are either end of a link of type alpha = x, y or z on the honeycomb lattice. The Kitaev model is exactly solvable and we show that this remains so in the presence of site dilution and exchange randomness. We find that vacancies bind a flux. In the gapped phase, a vacancy forms an effective paramagnetic moment. With two or more vacancies we describe the interaction of their effective moments and show that a finite density of vacancies leads to a divergent macroscopic susceptibility at small fields. In the gapless phase the effective moment has a susceptibility that is, to leading order at small fields, chi(h)~log(1/h). Interaction between the moments from two vacancies on opposite sublattices cuts off this divergence in susceptibility at a large but finite constant. Two vacancies on the same sublattice behave quite differently and we find the combined susceptibility is parametrically larger than that of an isolated vacancy, chi(h)sim [h(log(1/h))^{3/2}]^{-1}. We also investigate the effects of slowly varying, quenched disorder in exchange coupling. We demonstrate that this does not qualitatively affect the susceptibility but show that the heat capacity C ~ T^{2/z}, where z is a measure of the disorder and increases from one with increasing disorder strength.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20889号 / 理博第4341号 / 新制||理||1623(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 戸塚 圭介, 教授 川上 則雄, 教授 佐藤 昌利 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

The Kitaev model has become a source of much excitement in the field of condensed matter. It is a two dimensional model of spins ½ on a honeycomb lattice with bond-dependent interactions. Its interesting properties include a quantum spin liquid ground state and anyonic excitations. These properties could lead to exciting applications in quantum computing if materials were found to behave similarly to the Kitaev model. Such materials have been found, however the Kitaev model is too simple to describe these materials and additional interactions must be considered. The Heisenberg interaction is one such additional interaction. As such, we can define the Kitaev-Heisenberg model by combining the Kitaev and Heisenberg interactions. We can now ask ourselves if the quantum spin liquid ground state and anyonic excitations still exist in the Kitaev-Heisenberg model. To answer this question, a non-local string order parameter has been defined which is non-zero inside the quantum spin liquid phase and zero outside of it. This string order parameter was shown to exist and survive the Heisenberg interaction on the 2-leg ladder. In this thesis, we look to expand this result to multileg ladders such as the 3-leg, 4-leg, and 5-leg ladders to see if the string order parameter survives in the Kitaev-Heisenberg model in 2 dimensions. Our results show that the string order parameter does exist in multileg ladders, however the phase space window in which it survives the Heisenberg interaction is narrower than in the 2-leg ladder. / Thesis / Master of Science (MSc)

Thesis advisor: Michael J. Graf / Quantum spin liquids (QSL)’s have been one of the most hotly researched areas ofcondensed matter physics for the past decade. Yet, science has yet to unconditionally identify any one system as harboring a QSL state. This is because QSL’s are largely defined as systems whose electronic spins do not undergo a thermodynamic transition as T→0. Quantum spin liquids remain fully paramagnetic, including dynamical spin fluctuations, at T=0. As a result, distinguishing a QSL system from a conventionally disordered system remains an outstanding challenge. If a system spin freezes or magnetically orders, it cannot be a QSL. In this thesis I present published experiments I have performed on QSL candidate materials. By using muon spin rotation (μSR) and AC magnetic susceptibility I have evaluated the ground states of several candidates for the absence of long-range magnetic disorder and low-temperature spin-fluctuations. For the systems which order or spin-freeze, my research provided key knowledge to the field of frustrated magnetism. The systems I studied are as follows: The geometrically frustrated systems NaYbO2 and LiYbO2; the Kitaev honeycomb systems Cu2IrO3 and Ag3LiIr2O6; and the metallic kagome system KV3Sb5. Each of these systems brought new physics to the field of frustrated magnetism. NaYbO2 is a promising QSL candidate. LiYbO2 harbors an usual form of spiral incommensurate order that has a staggered transition. Cu2IrO3 has charge state disorder that results in a magnetically inhonogenious state. Ag3LiIr2O6 illustrates the role structural disorder plays in disguising long-range magnetic order. And finally, KV3Sb5 isn’t conventionally magnetic at all; our measurements ruled out ionic magnetism and uncovered a type-II superconductor. Our measurements on KV3Sb5 stimulated further research into KV3Sb5 and it’s unconventional electronic states. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Eine Vielzahl von interessanten Phänomenen entsteht durch die quantenmechanischeWechselwirkung einer großen Zahl von Teilchen. In den meisten Fällen ist die Beschreibung der relevanten physikalischen Eigenschaften extrem schwierig, da die Komplexität des Systems exponentiell mit der Anzahl der wechselwirkenden Teilchen anwächst und das Lösen der zugrunde liegenden Schrödingergleichung unmöglich macht. Trotzdem gab es in der Geschichte der Festkörperphysik eine Reihe von bahnbrechenden Entdeckungen, die unser Verständnis von komplexen Phänomenen deutlich voran gebracht haben. Dazu zählt die Entwicklung der Landau’schen Theorie der Fermiflüssigkeit, der BCS-Theorie der Supraleitung, der Theorie der Supraflüssigkeit und der Theorie des fraktionalen Quanten-Hall-Effekts. In all diesen Fällen ist ein theoretisches Verständnis mithilfe sogenannter Quasiteilchen gelungen. Anstatt ein komplexes Phänomen durch das Verhalten von fundamentalen Teilchen wie der Elektronen zu erklären, ist es möglich, die entsprechenden Eigenschaften durch das simple Verhalten von Quasiteilchen zu beschreiben, die allein auf Grund der komplexen kollektiven Wechselwirkung entstehen. Eines der seltenen Beispiele, bei dem ein stark korreliertes quantenmagnetisches Problem analytisch lösbar ist, ist das Kitaev Modell. Es beschreibt wechselwirkende Spins auf einem Sechseck-Gitter und zeichnet sich durch einen Spinflüssigkeits-Grundzustand aus. Auch hier gelang die Lösung mittels spezieller Quasiteilchen, den Majorana Fermionen. Experimentell ist es jedoch noch nicht gelungen eine Spinflüssigkeit eindeutig nachzuweisen, da diese sich gerade durch das Fehlen jeglicher klassischer Ordnung und üblicher experimenteller Kenngrößen auszeichnet. Dagegen kann die Beobachtung von Quasiteilchenanregungen einen Hinweis auf den zugrunde liegenden Zustand liefern. Aber auch der definitive Nachweis von Majorana Fermionen in jeglicher Art System, bleibt ein ausstehendes Ziel in der modernen Festkörperphysik. Diese Arbeit befasst sich daher mit der Frage, wie solche Quasiteilchen experimentell sichtbar gemacht werden könnten. Dazu untersuchen wir den Einfluss von Unordnung auf die Zustände und Messgrößen des Kitaev Modells. Dies ist in zweierlei Hinsicht relevant. Einerseits ist Unordnung in der Natur allgegenwärtig, andererseits kann sie auch strategisch herbeigeführt werden, um die Reaktion eines System gezielt zu testen. Das zentrale Ergebnis dieser Arbeit ist, dass den Majorana Fermionen dabei in der Tat eine physikalische, messbare Bedeutung zukommt. Die Arbeit beginnt mit einer Einführung in frustrierte quantenmagnetische Systeme und Spinflüssigkeiten und diskutiert einige Effekte, die durch Gitterverzerrungen oder Verunreinigungen entstehen können. Anschließend zeigen wir, wie sich durch die frustrierte Wechselwirkung im Kitaev Modell ein Spinflüssigkeits-Grundzustand herausbildet. Die analytische Lösung des Modells gelingt mit Hilfe von Majorana Fermionen, jedoch verdoppelt sich der Hilbertraum pro Spin durch die Einführung dieser Quasiteilchen. Ein zentraler Aspekt dieser Arbeit ist daher die richtige Auswahl der „physikalischen“ Zustände, also solcher, die einem Zustand im ursprünglichen Spin Modell entsprechen. Dabei unterscheiden wir zwischen offenen und periodischen Randbedingungen. Wir konnten beweisen, dass sich, in der Phase ohne Bandlücke und für periodische Systeme, stets ein angeregtes Fermion befindet. Dies führt zu großen Effekten in endlichen Systemen, wie wir anhand der Suszeptibilität und der Anregungslücke für magnetische Flüsse zeigen. Außerdem berechnen wir numerisch die statische und dynamische Suszeptibilität abhängig von der Unordnung in der Wechselwirkungsstärke. Diese Art der Unordnung entsteht beispielsweise durch unregelmäßige Gitterstrukturen oder chemische Verunreinigungen auf den nicht-magnetischen Gitterplätzen. Insbesondere ergibt die Verteilung der lokalen Suszeptibilitäten das Linienspektrum, welches sich in Kernspinresonanz Experimenten messen lässt. Für große Unordnung postulieren wir einen Übergang zu einem Zustand mit einer zufälligen Verteilung magnetischer Flüsse. Ein weiterer Kern der Dissertation ist die Untersuchung eines magnetischen Defekts im Kitaev Modell. Diese Situation beschreibt den ungewöhnlichen Fall eines Kondoeffekts in einer Spinflüssigkeit. In der Majorana Fermionen Darstellung gelingt es uns, das Problem in eine Form zu bringen, die mit Hilfe von Wilson’s numerischer Renormalisierungsgruppe untersucht werden kann. Es zeigt sich, dass dadurch eine Nullpunktsentropie des Defekts entsteht, die durch lokalisierte Majorana Fermionen erklärt werden kann. Durch die Darstellung des Kitaev Modells mithilfe von Quasiteilchen ist es möglich eine elegante Beschreibung eines komplexen, stark wechselwirkenden Systems zu finden. Die Ergebnisse dieser Arbeit zeigen, dass den Majorana Fermionen dabei durchaus eine physikalische Bedeutung zukommt. Gelingt es sie z.B. durch magnetische Störstellen zu lokalisieren, wäre ein direkter experimenteller Nachweis möglich. / Many interesting phenomena in quantum physics arise through the quantum mechanical interaction of a large number of particles. In most cases describing the relevant physical properties is extremely difficult, because the complexity of the system increases exponentially with the number of interacting particles and solving the underlying Schrödinger equation becomes impossible. Nevertheless, our understanding of complex phenomena has progressed through some groundbreaking discoveries in the history of condensed matter physics. Examples include the development of Landau’s theory of Fermi liquids, the BCStheory of superconductivity, the theory of superfluidity and the theory of the fractional quantum Hall effect. In all these cases a theoretical understanding was achieved with so-called quasi-particles. Instead of explaining a phenomenon through the behavior of fundamental particles, such as electrons, the corresponding properties can be described by the simple behavior of quasi-particles, which are themselves a result of the complex collective interaction. One of the rare examples, where a strongly correlated quantum mechanical problem can be solved analytical, is the Kitaev model. It describes interacting spins on a honeycomb lattice and exhibits a spin liquid ground state. Here the solution was achieved by means of certain quasi-particles, called Majorana fermions. However, it has not been possible to clearly identify such a spin liquid experimentally, because its defining feature is the absence of any conventional order, in particular magnetic order. In contrast, the observation of quasiparticle excitations may hint at the nature of the ground state. But also a definite detection of Majorana fermions in any kind of system remains one of the outstanding issues in modern condensed matter physics. Therefore this thesis is devoted to the question how such quasiparticles may be found experimentally. For this reason we study the influence of disorder on the states and observables of the Kitaev model. This is relevant in two respects: Firstly, disorder is ubiquitous in nature and secondly, it may be used strategically to probe the response of a system. The central result of this work is that Majorana fermions hereby indeed obtain a true physical and observable significance. The thesis starts with an introduction of frustrated quantum mechanical systems and spin liquids, and discusses some of the effects that arise through lattice distortions or impurities. Afterwards we show how the frustrated interactions in the Kitaev model lead to a spin liquid ground state. The analytical solution of the model is achieved through the introduction of Majorana fermions. However, resulting from the introduction of these quasi-particles the Hilbert space per spin doubles. A central aspect of this thesis is therefore the right selection of the “physical” states, which correspond to a state of the original spin Hamiltonian. To do this, we distinguish between periodic and open boundary conditions explicitly. We were able to prove that there is always one excited fermion in the gapless phase of the periodic system. This leads to large finite-size effects, as we will illustrate for the susceptibility and the magnetic flux gap. Moreover we compute the static and dynamic spin susceptibilities for finite-size systems subject to disorder in the exchange couplings. In a possible experimental realization, this kind of disorder arises from lattice distortions or chemical disorder on nonmagnetic sites. Specifically, we calculate the distribution of local susceptibilities and extract the lineshape, which can be measured in nuclear-magnetic-resonance experiments. Further, for increasing disorder we predict a transition to a random-flux state. Another core of this dissertation is the investigation of a magnetic impurity in the Kitaev model. This setup represents the unusual case of a Kondo effect in a quantum spin liquid. Utilizing the Majorana representation we are able to formulate the problem in a way that can be analyzed using Wilson’s numerical renormalization group. The numerics reveal an impurity entropy which can be explained by localized Majorana fermions. Through the representation of the Kitaev model in terms of quasi-particles an elegant description of a complex, strongly correlated system is possible. The results of this thesis indicate that these Majorana acquire a relevant physical meaning. If one can localize them, for example with the help of magnetic impurities, a direct experimental observation would be feasible.

Submitted by LUCIANO HENRIQUE SILIANO RICCO null (luciano.silianoricco@gmail.com) on 2016-03-03T12:32:48Z No. of bitstreams: 1 Dissertação_LucianoRicco.pdf: 7937141 bytes, checksum: 4631857aac8f308808dda1e44b0c0f03 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-04T16:21:23Z (GMT) No. of bitstreams: 1 ricco_lhs_me_ilha.pdf: 7937141 bytes, checksum: 4631857aac8f308808dda1e44b0c0f03 (MD5) / Made available in DSpace on 2016-03-04T16:21:23Z (GMT). No. of bitstreams: 1 ricco_lhs_me_ilha.pdf: 7937141 bytes, checksum: 4631857aac8f308808dda1e44b0c0f03 (MD5) Previous issue date: 2016-01-29 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Investigou-se teoricamente um sistema composto por um interferômetro do tipo Aharonov- Bohm com dois pontos quânticos, onde um deles encontra-se acoplado à um fio de Kitaev na fase topológica, nos casos em que se desconsidera a interação de Coulomb entre os pontos quânticos (caso não interagente) e quando a mesma é levada em conta (caso interagente). Na primeira situação, verificou-se a presença robusta da anomalia de voltagem zero para ambos os regimes de interferência Fano adotados. Além do mais, constatou-se que o estado de Majorana isolado possui uma maneira singular de quebrar a simetria dos perfis de densidade de transmitância em função da diferença simétrica de energia dos pontos quânticos e da energia de Fermi dos terminais metálicos. Tais perfis podem ser obtidos experimentalmente por medidas de condutância. Na situação de pontos quânticos interagentes em ressonância, verificou-se que a razão entre a magnitude da repulsão de Coulomb e o acoplamento fio-ponto quântico altera a largura da anomalia de voltagem zero em ambos os regimes Fano analisados. Esse fato sugere que a correlação eletrônica influencia o tempo de vida do estado de Majorana no ponto quântico hibridizado diretamente com o fio. Ademais, para a situação de pontos quânticos não ressonantes, a inversão dos valores de energia dos mesmos também modifica a largura da anomalia de voltagem zero, fenômeno que não ocorre para o caso não interagente. Acredita-se que o dispositivo proposto neste trabalho constitui um mecanismo experimental alternativo para detectar excitações de Majorana. / We investigate theoretically a setup composed by an Aharonov-Bohm-like interferometer with two quantum dots, where one of them is coupled to a Kitaev wire within the topological phase, which is explored in two cases: (i) the interdot Coulomb correlation is disregarded (noninteracting case) and (ii) the same is taken into account (interacting case). In the situation (i), we verify the presence of the zero-bias anomaly for the both Fano regimes of interference adopted. Furthermore, we found that an isolated Majorana state has a particular way of breaking the symmetry in transmittance profiles, which can be accessed experimentally by performing electrical conductance measurements. In the situation (ii), for interacting quantum dots in resonance, we notice that the ratio between the Coulomb repulsion strength and the wire-dot coupling changes the width of the zero-bias peak for both Fano regimes analyzed. This feature suggests that the electronic correlation modifies the Majorana state lifetime in the dot directly coupled to the wire. Moreover, for the off-resonance situation, the swap between the energy levels of the dots also changes the width of the Majorana peak, which is not observed in the noninteracting case. The results obtained here can guide experimentalists that pursuit a way of revealing Majorana signatures. / FAPESP: 2014/14143-0