Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets
The present thesis presents several theoretical studies on the dynamical processes of physicochemical interest involving superfluid helium (4He) nanodroplets. It has been developed a theoretical approach and computationally implemented. This consists in the first stage on the theoretical study of ch...
| Autor: | |
|---|---|
| Tipo de documento: | tese |
| Estado: | Versão publicada |
| Data de publicação: | 2015 |
| País: | España |
| Recursos: | CBUC, CESCA |
| Repositório: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/313040 |
| Acesso em linha: | http://hdl.handle.net/10803/313040 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Nanoquímica Nanochemistry Heli líquid Helio líquido Liquid helium Reaccions químiques Reacciones químicas Chemical reactions Transferència d'energia Transferencia de energía Energy transfer Líquids quàntics Líquidos cuánticos Quantum liquids Ciències Experimentals i Matemàtiques 544 |
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Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| title |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| spellingShingle |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets Vilà Casanovas, Arnau Nanoquímica Nanochemistry Heli líquid Helio líquido Liquid helium Reaccions químiques Reacciones químicas Chemical reactions Transferència d'energia Transferencia de energía Energy transfer Líquids quàntics Líquidos cuánticos Quantum liquids Ciències Experimentals i Matemàtiques 544 |
| title_short |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| title_full |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| title_fullStr |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| title_full_unstemmed |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| title_sort |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodroplets |
| dc.creator.none.fl_str_mv |
Vilà Casanovas, Arnau |
| author |
Vilà Casanovas, Arnau |
| author_facet |
Vilà Casanovas, Arnau |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
González Pérez, Miguel Mayol Sánchez, Ricardo Universitat de Barcelona. Departament de Química Física |
| dc.subject.none.fl_str_mv |
Nanoquímica Nanochemistry Heli líquid Helio líquido Liquid helium Reaccions químiques Reacciones químicas Chemical reactions Transferència d'energia Transferencia de energía Energy transfer Líquids quàntics Líquidos cuánticos Quantum liquids Ciències Experimentals i Matemàtiques 544 |
| topic |
Nanoquímica Nanochemistry Heli líquid Helio líquido Liquid helium Reaccions químiques Reacciones químicas Chemical reactions Transferència d'energia Transferencia de energía Energy transfer Líquids quàntics Líquidos cuánticos Quantum liquids Ciències Experimentals i Matemàtiques 544 |
| description |
The present thesis presents several theoretical studies on the dynamical processes of physicochemical interest involving superfluid helium (4He) nanodroplets. It has been developed a theoretical approach and computationally implemented. This consists in the first stage on the theoretical study of chemical reaction dynamics in superfluid helium nanodroplets. The description of the system is fully quantum and consists in a hybrid method in which different theoretical approaches are combined to describe the different components of the system. The liquid helium (superfluid) has been described through the Density Functional Theory (DFT), using a phenomenological energy functional. Atomic and molecular impurities have been described by means of standard quantum dynamics. The methodology developed in the present thesis has been applied to the study of various physicochemical processes of interest. These studies con be grouped as: - Study of the structure, energy and electronic spectroscopy of helium nanodroplets doped with atomic oxygen in different electronic states. In this work, the influence of the electronic state of oxygen and energy structure of the drop has been determined to be the induction of anisotropy on the helium density (for the open-shell cases), as well as the high quality of helium nanodroplets acting as a matrix for high-resolution spectroscopy confirmed. - Investigation on the dynamics of the photodissociation of homonuclear diatomic molecules in superfluid helium nanodroplets. In this context, the method developed has been initially applied to the case of molecular chlorine. Some interesting results related with the energy exchange phenomenon and generation of quantum (confined) resonances due tot the interaction of the molecules with the helium nanodroplet have been reported. Moreover, the relaxation process of the nanodroplet after the photodissociation has been also studied. This methodology developed has been also applied to the case of two halogen homonuclear diatomic molecules more, Br2 and I2. Different phenomenology and mechanism have been found for these cases, even producing full recombination for the biggest droplet considered. Furthermore, in order to determine the role played by the mass of the atoms of the diatomic homonuclear molecule on this process, we have studied the photodissociation dynamics of prototypic “isomers” of Cl2. - We have modeled the process of the capture of a neon atom by superfluid helium nanodroplets. We have restricted to the case of zero angular momentum as a first approach to the problem at the quantum level. We obtained the time scale of this process. Also, it was found that the energy exchange does not take place at any time, but until the velocity is low enough (Landau’s critical velocity) there is no mechanism for the exchange energy. This leads to a constant (mean) velocity of the quantum particle (Ne atom), since the friction force is zero. The resulting wave packet in momentum representation has a Gaussian type profile. - The synthesis reaction of a dimer of van der Waals (Ne2) in helium nanodroplets has been investigated. This process starts with a drop initially doped with Ne atom. Then, a second Ne atom is captured, which initiates the process of the synthesis. We have restricted to the zero angular momentum case for computational reasons. A great variety of phenomenology (reaction mechanisms) depending on the collision velocity and the droplet size has been found. |
| publishDate |
2015 |
| dc.date.none.fl_str_mv |
2015 2015 2015 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion |
| format |
doctoralThesis |
| status_str |
publishedVersion |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10803/313040 |
| url |
http://hdl.handle.net/10803/313040 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.format.none.fl_str_mv |
213 p. application/pdf application/pdf |
| dc.publisher.none.fl_str_mv |
Universitat de Barcelona |
| publisher.none.fl_str_mv |
Universitat de Barcelona |
| dc.source.none.fl_str_mv |
TDX (Tesis Doctorals en Xarxa) reponame:TDR. Tesis Doctorales en Red instname:CBUC, CESCA |
| instname_str |
CBUC, CESCA |
| reponame_str |
TDR. Tesis Doctorales en Red |
| collection |
TDR. Tesis Doctorales en Red |
| repository.name.fl_str_mv |
|
| repository.mail.fl_str_mv |
|
| _version_ |
1869425374564188160 |
| spelling |
Quantum dynamics of physicochemical processes in superfluid (4)He nanodropletsVilà Casanovas, ArnauNanoquímicaNanochemistryHeli líquidHelio líquidoLiquid heliumReaccions químiquesReacciones químicasChemical reactionsTransferència d'energiaTransferencia de energíaEnergy transferLíquids quànticsLíquidos cuánticosQuantum liquidsCiències Experimentals i Matemàtiques544The present thesis presents several theoretical studies on the dynamical processes of physicochemical interest involving superfluid helium (4He) nanodroplets. It has been developed a theoretical approach and computationally implemented. This consists in the first stage on the theoretical study of chemical reaction dynamics in superfluid helium nanodroplets. The description of the system is fully quantum and consists in a hybrid method in which different theoretical approaches are combined to describe the different components of the system. The liquid helium (superfluid) has been described through the Density Functional Theory (DFT), using a phenomenological energy functional. Atomic and molecular impurities have been described by means of standard quantum dynamics. The methodology developed in the present thesis has been applied to the study of various physicochemical processes of interest. These studies con be grouped as: - Study of the structure, energy and electronic spectroscopy of helium nanodroplets doped with atomic oxygen in different electronic states. In this work, the influence of the electronic state of oxygen and energy structure of the drop has been determined to be the induction of anisotropy on the helium density (for the open-shell cases), as well as the high quality of helium nanodroplets acting as a matrix for high-resolution spectroscopy confirmed. - Investigation on the dynamics of the photodissociation of homonuclear diatomic molecules in superfluid helium nanodroplets. In this context, the method developed has been initially applied to the case of molecular chlorine. Some interesting results related with the energy exchange phenomenon and generation of quantum (confined) resonances due tot the interaction of the molecules with the helium nanodroplet have been reported. Moreover, the relaxation process of the nanodroplet after the photodissociation has been also studied. This methodology developed has been also applied to the case of two halogen homonuclear diatomic molecules more, Br2 and I2. Different phenomenology and mechanism have been found for these cases, even producing full recombination for the biggest droplet considered. Furthermore, in order to determine the role played by the mass of the atoms of the diatomic homonuclear molecule on this process, we have studied the photodissociation dynamics of prototypic “isomers” of Cl2. - We have modeled the process of the capture of a neon atom by superfluid helium nanodroplets. We have restricted to the case of zero angular momentum as a first approach to the problem at the quantum level. We obtained the time scale of this process. Also, it was found that the energy exchange does not take place at any time, but until the velocity is low enough (Landau’s critical velocity) there is no mechanism for the exchange energy. This leads to a constant (mean) velocity of the quantum particle (Ne atom), since the friction force is zero. The resulting wave packet in momentum representation has a Gaussian type profile. - The synthesis reaction of a dimer of van der Waals (Ne2) in helium nanodroplets has been investigated. This process starts with a drop initially doped with Ne atom. Then, a second Ne atom is captured, which initiates the process of the synthesis. We have restricted to the zero angular momentum case for computational reasons. A great variety of phenomenology (reaction mechanisms) depending on the collision velocity and the droplet size has been found.La present Tesi doctoral comprèn diferents estudis teòrics sobre processos fisicoquímics relacionats amb nanogotes d'heli (4He) superfluid. Per a la seva realització s'ha desenvolupat la metodologia teòrica i implementat a nivell computacional. Es tracta d'un primer estudi teòric en qual s'estudia la dinàmica de reaccions químiques en nanogotes d'heli superfluid. La descripció del sistema és completament quàntica, combinant diferents aproximacions teòriques per descriure els components del sistema. L'heli líquid s'ha descrit a través de la teoria del funcional de la densitat (DFT), utilitzant un funcional fenomenològic. Les impureses atòmiques i moleculars s'han descrit mitjançant dinàmica quàntica. La metodologia desenvolupada ha estat aplicada a l'estudi de diversos processos d'interès quimicofísic. Aquests són: - Estudi de l'estructura, energètica i espectroscòpia electrònica de nanogotes d'heli dopades amb oxigen atòmic en diferents estats electrònics. - Estudi de la dinàmica de la fotodissociació de molècules diatòmiques homonuclears en nanogotes d'heli superfluid. El mètode desenvolupat s'ha aplicat inicialment al cas del clor molecular. Posteriorment s'ha realitzat els casos del brom i el iode, així com d'"isòtops" artificials del clor amb l'objecte de determinar la influència de la massa sobre aquest tipus de processos. S’ha pogut determinar la formació de ressonàncies quàntiques, les qual s’han estudiat amb detall posteriorment. - Modelització del procés de captura d'un àtom de neó per part de nanogotes d'heli superfluid. S'ha estudiat el cas de moment angular nul com una primera aproximació a la problemàtica a nivell quàntic. - Reacció de síntesi d'un dímer de van der Waals (Ne2) en nanogotes d'heli. Partint d'una gota inicialment dopada amb un àtom de Ne, la captura d'un segon àtom de Ne inicia el procés de la síntesi. S'ha determinat una gran varietat de fenomenologia (mecanismes de reacció) segons la velocitat de col·lisió i la mida de la gota.Universitat de BarcelonaGonzález Pérez, MiguelMayol Sánchez, RicardoUniversitat de Barcelona. Departament de Química Física201520152015info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersion213 p.application/pdfapplication/pdfhttp://hdl.handle.net/10803/313040TDX (Tesis Doctorals en Xarxa)reponame:TDR. Tesis Doctorales en Redinstname:CBUC, CESCAInglésADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs.info:eu-repo/semantics/openAccessoai:www.tdx.cat:10803/3130402026-06-14T12:46:07Z |
| score |
15,300724 |