Preventing decoherence with giant atoms
Doctoral thesis, 2025
Giant atoms have emerged as a new paradigm in quantum optics during the last decade. These are quantum emitters that couple to light—or other bosonic fields—at multiple discrete points, which can be spaced wavelengths apart. In the short time since the giant-atom regime was first reached, it has been shown that they offer more possibilities for design, control, and tunability than small atoms do, which makes them promising assets for quantum technologies. At the same time, due to the novelty of the field, most works have only studied giant atoms in relatively simple setups, e.g., coupled to open continuous waveguides. Thus, the papers appended here are an attempt to broaden the field by studying giant atoms in environments that have not been explored in depth before: continuous waveguides with chiral coupling and structured baths.
In this thesis, we contextualize the papers with regards to previously existing knowledge and future applications in the fields of quantum optics and quantum technology. We also provide a detailed description of the analytical tools that are necessary to derive the results of the appended papers: we delve into Lindbladian master equations, SLH formalism, and resolvent formalism, and we focus particularly on the underlying assumptions and approximations behind these techniques.
In this thesis, we contextualize the papers with regards to previously existing knowledge and future applications in the fields of quantum optics and quantum technology. We also provide a detailed description of the analytical tools that are necessary to derive the results of the appended papers: we delve into Lindbladian master equations, SLH formalism, and resolvent formalism, and we focus particularly on the underlying assumptions and approximations behind these techniques.
waveguide quantum electrodynamics
continuous waveguides
resolvent formalism
Quantum optics
structured waveguides
master equation
SLH formalism
giant atoms
artificial atoms
open quantum systems
Kollektorn, MC2, Chalmers
Opponent: Peter Rabl, TU Munich / Walther-Meißner-Institute
Author
Ariadna Soro Álvarez
Applied Quantum Physics PhD Students
Interaction between giant atoms in a one-dimensional structured environment
Physical Review A,;Vol. 107(2023)
Journal article
Avoiding decoherence with giant atoms in a two-dimensional structured environment
Physical Review Research,;Vol. 6(2024)
Journal article
The basic principles of quantum physics underpin many of the technologies we use today—from lasers, to GPS, to smartphones. Now, a new generation of quantum technologies is emerging, potentially leading to even more transformative breakthroughs. A key challenge in the development of these new technologies is getting rid of decoherence: the gradual loss of quantum information due to unwanted interactions with the environment.
This thesis, titled "Preventing decoherence with giant atoms", explores a recently discovered class of quantum emitters known as giant atoms.
Unlike traditional atoms, which interact with light as a single localized point in space, giant atoms can couple to light at multiple spatially separated points. This means that they effectively interfere with themselves, a feature which we can harness to suppress decoherence and enhance control over quantum systems.
While earlier studies of giant atoms focused on their coupling to relatively simple environments, this work broadens the field by studying their behavior in more complex settings, such as chiral waveguides and structured photonic baths. The results found here offer a deeper understanding of fundamental light-matter interactions, as well as new insights into the stabilization and manipulation of quantum states—which may find applications in the design of quantum computers, quantum communication networks, and other quantum technologies.
This thesis, titled "Preventing decoherence with giant atoms", explores a recently discovered class of quantum emitters known as giant atoms.
Unlike traditional atoms, which interact with light as a single localized point in space, giant atoms can couple to light at multiple spatially separated points. This means that they effectively interfere with themselves, a feature which we can harness to suppress decoherence and enhance control over quantum systems.
While earlier studies of giant atoms focused on their coupling to relatively simple environments, this work broadens the field by studying their behavior in more complex settings, such as chiral waveguides and structured photonic baths. The results found here offer a deeper understanding of fundamental light-matter interactions, as well as new insights into the stabilization and manipulation of quantum states—which may find applications in the design of quantum computers, quantum communication networks, and other quantum technologies.
Quantum simulation and communication with giant atoms
Swedish Foundation for Strategic Research (SSF) (FFL21-0279), 2022-08-01 -- 2027-12-31.
Wallenberg Centre for Quantum Technology (WACQT)
Knut and Alice Wallenberg Foundation (KAW 2017.0449, KAW2021.0009, KAW2022.0006), 2018-01-01 -- 2030-03-31.
Giant atoms - a new regime in quantum optics
Swedish Research Council (VR) (2019-03696), 2020-01-01 -- 2023-12-31.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Nano-technology
Other Physics Topics
Areas of Advance
Nanoscience and Nanotechnology
Roots
Basic sciences
ISBN
978-91-8103-220-8
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5678
Publisher
Chalmers