Publications

Order by: publication date number of citations

• An introduction to the surface code

  Andrew N. Cleland

  SciPost Phys. Lect. Notes 49 (2022) · published 3 May 2022 | Toggle abstract · pdf

  This chapter provides an introduction to the surface code, discussing details about how physical qubits are connected and operated to create logical qubits, how errors are handled, and what performance metrics are needed to generate logical qubits with performance that exceeds their underlying physical qubit performance.

  4 citations

• Sub-GeV dark matter models and direct detection

  Tongyan Lin

  SciPost Phys. Lect. Notes 43 (2022) · published 18 March 2022 | Toggle abstract · pdf

  Lecture notes for Les Houches Summer School 2021: Dark Matter. These lectures give a brief introduction to sub-GeV dark matter models, and then reviews theory and approaches to direct detection of sub-GeV dark matter.

  4 citations

• The unitary representations of the Poincar\'e group in any spacetime dimension

  Xavier Bekaert, Nicolas Boulanger

  SciPost Phys. Lect. Notes 30 (2021) · published 14 June 2021 | Toggle abstract · pdf

  An extensive group-theoretical treatment of linear relativistic field equations on Minkowski spacetime of arbitrary dimension $D\geqslant 3$ is presented. An exhaustive treatment is performed of the two most important classes of unitary irreducible representations of the Poincar\'e group, corresponding to massive and massless fundamental particles. Covariant field equations are given for each unitary irreducible representation of the Poincar\'e group with non-negative mass-squared.

  4 citations

• Four lectures on Euler integrals

  Saiei-Jaeyeong Matsubara-Heo, Sebastian Mizera, Simon Telen

  SciPost Phys. Lect. Notes 75 (2023) · published 26 October 2023 | Toggle abstract · pdf

  These lecture notes provide a self-contained introduction to Euler integrals, which are frequently encountered in applications. In particle physics, they arise as Feynman integrals or string amplitudes. Our four selected topics demonstrate the diverse mathematical techniques involved in the study of Euler integrals, including polyhedral geometry, very affine varieties, differential equations, and computational algebra.

  3 citations

• Covariant canonical formulations of classical field theories

  Francois Gieres

  SciPost Phys. Lect. Notes 77 (2023) · published 5 December 2023 | Toggle abstract · pdf

  We review in simple terms the covariant approaches to the canonical formulation of classical relativistic field theories (in particular gauge field theories and general relativity) and we discuss the relationships between these approaches as well as the relation with the standard (non-covariant) Hamiltonian formulation. Particular attention is paid to conservation laws (notably related to geometric symmetries) within the different approaches. Moreover, for each of these approaches, the impact of space-time boundaries is also addressed. To make the text accessible to a wider audience, we have included an outline of Poisson and symplectic geometry for both classical mechanics and field theory.

  3 citations

• Quantum enhanced metrology in the search for fundamental physical phenomena

  Konrad W. Lehnert

  SciPost Phys. Lect. Notes 40 (2022) · published 11 March 2022 | Toggle abstract · pdf

  These notes summarize lectures given at the 2019 Les Houches summer school on Quantum Information Machines. They describe and review an application of quantum metrology concepts to searches for ultralight dark matter. In particular, for ultralight dark matter that couples as a weak classical force to a laboratory harmonic oscillator, quantum squeezing benefits experiments in which the mass of the dark matter particle is unknown. This benefit is present even if the oscillatory dark matter signal is much more coherent than the harmonic oscillator that it couples to, as is the case for microwave frequency searches for dark matter axion particles.

  3 citations

• From classical to quantum regime of topological surface states via defect engineering

  Maryam Salehi, Xiong Yao, Seongshik Oh

  SciPost Phys. Lect. Notes 58 (2022) · published 21 July 2022 | Toggle abstract · pdf

  Since the notion of topological insulator (TI) was envisioned in late 2000s, topology has become a new paradigm in condensed matter physics. Realization of topology as a generic property of materials has led to numerous predictions of topological effects. Although most of the classical topological effects, directly resulting from the presence of the spin-momentum-locked topological surface states (TSS), were experimentally confirmed soon after the theoretical prediction of TIs, many topological quantum effects remained elusive for a long while. It turns out that native defects, particularly interfacial defects, have been the main culprit behind this impasse. Even after quantum regime is achieved for the bulk states, TSS still tends to remain in the classical regime due to high density of interfacial defects, which frequently donate mobile carriers due to the very nature of the topologically-protected surface states. However, with several defect engineering schemes that suppress these effects, a series of topological quantum effects have emerged including quantum anomalous Hall effect, quantum Hall effect, quantized Faraday/Kerr rotations, topological quantum phase transitions, axion insulating state, zeroth-Landau level state, etc. Here, we review how these defect engineering schemes have allowed topological surface states to pull out of the murky classical regime and reveal their elusive quantum signatures, over the past decade.

  3 citations

• New directions in the search for dark matter

  Surjeet Rajendran

  SciPost Phys. Lect. Notes 56 (2022) · published 23 May 2022 | Toggle abstract · pdf

  The identification of the nature of dark matter is one of the most important problems confronting particle physics. Current observational constraints permit the mass of the dark matter to range from $\sim 10^{-22}$ eV - $10^{48}$ GeV. Given the weak nature of these bounds and the ease with which dark matter models can be constructed, it is clear that the problem can only be solved experimentally. In these lectures, I discuss methods to experimentally probe a wide range of dark matter candidates.

  3 citations

• Introduction to Monte Carlo for matrix models

  Raghav G. Jha

  SciPost Phys. Lect. Notes 46 (2022) · published 4 April 2022 | Toggle abstract · pdf

  We consider a wide range of matrix models and study them using the Monte Carlo technique in the large N limit. The results we obtain agree with exact analytic expres- sions and recent numerical bootstrap methods for models with one and two matrices. We then present new results for several unsolved multi-matrix models where no other tool is yet available. In order to encourage an exchange of ideas between different numerical approaches to matrix models, we provide programs in Python that can be easily modified to study potentials other than the ones discussed. These programs were tested on a laptop and took between a few minutes to several hours to finish depending on the model, N, and the required precision.

  2 citations

• KPZ fluctuations in finite volume

  Sylvain Prolhac

  SciPost Phys. Lect. Notes 81 (2024) · published 12 June 2024 | Toggle abstract · pdf

  These lecture notes, adapted from the habilitation thesis of the author, survey in a first part various exact results obtained in the past few decades about KPZ fluctuations in one dimension, with a special focus on finite volume effects describing the relaxation to its stationary state of a finite system starting from a given initial condition. The second part is more specifically devoted to an approach allowing to express in a simple way the statistics of the current in the totally asymmetric simple exclusion process in terms of a contour integral on a compact Riemann surface, whose infinite genus limit leads to KPZ fluctuations in finite volume.

  2 citations