Manipulating quantum information with atomic vapour

• Grant number: 21/04023-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2021
• End date: February 28, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Marcelo Martinelli
• Grantee: Théo Louzada Meireles
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/18834-0 - Exploring quantum information with atoms, crystals and chips, AP.TEM

Abstract

We are looking for the generation of entangled states for applications in quantum information processing. The goal is generation of a scalable structure of entangled modes. This entanglement allows the sharing of information in a secure way by quantum cryptography protocols between the players (Alice and Bob), and allows the development of systems for information processing that should overcome the present systems, that are based in classical information theory principles. We will use a parametric amplifier built on a rubidium vapor cell, at room temperature, that will produce a par of entangled beams. After that, by the precise engineering of the frequency spectra of the pump, we will entangle multiple modes of the field, resulting in a structure of multiple entangled modes, in a cluster state. This structure has the capability of use in information processing at the quantum level, based on a system whose number of modes can be arbitrarily extended in a net of entangled fields. The student will focus on the engineering of the pump mode, using distinct techniques for laser control. He will work on a Ti:sapphire laser, and stabilize this source to another laser that will serve as a reference. This will allow the controlled superposition of two distinct pump modes that will be injected into the vapor cell, forming the parametric amplifier.