Towards a quantum simulator emulating the electron-phonon interaction

The interaction between electrons and phonons lies behind a plethora of exotic physical phenomena, from Mott insulators and ferromagnetism to superconductivity. This interaction is really complex, and classical simulation methods fall short. Here is where analog quantum simulators come in. One can t...

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Detalles Bibliográficos
Autor: Mascaró Burguera, Lucas
Tipo de recurso: tesis de maestría
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/403232
Acceso en línea:https://hdl.handle.net/2117/403232
Access Level:acceso abierto
Palabra clave:Carbon nanotubes
Quantum dots
Nanotechnology
carbon nanotubes
quantum dots
electromechanics
nanotechnology
quantum simulators
Nanotubs de carbon
Punts quàntics
Nanotecnologia
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació
Àrees temàtiques de la UPC::Física::Mecànica quàntica
Descripción
Sumario:The interaction between electrons and phonons lies behind a plethora of exotic physical phenomena, from Mott insulators and ferromagnetism to superconductivity. This interaction is really complex, and classical simulation methods fall short. Here is where analog quantum simulators come in. One can take advantage of the outstanding mechanical and electronic properties of carbon nanotubes to couple their electronic degrees of freedom to their mechanical modes. This platform would allow for the first realization of an analog quantum simulator for the electron-phonon interaction, effectively realising a Hubbard Hamiltonian. Quantum dots are to be electrostatically defined in a carbon nanotube, and the electronic states are to be coupled to the mechanical modes. The realization of such a simulator requires extremely clean suspended semiconducting nanotubes, high coupling and fast and sensitive readout for the interdot transitions. This work presents a fabrication method to obtain this kind of devices and their characterization at cryogenic temperatures. Fast and sensitive readout is achieved by using RF reflectometry to study the conduction changes in an adjacent quantum dot used as a SET sensor. Only single quantum dots have been defined in the devices, since really good devices have yet to been cooled down. Single charge transition events have yet to be measured, and the reflectometry measurements need to be optimized. The overall progress of the project is promising, and the first devices have been already produced.