Publications associées à Fluctuation quantique

Ultra-high quantum coherent and scalable superconducting circuit optomechanics, from topological lattices to quantum storage

Mechanical oscillators can exhibit modes with ultra-low energy dissipation and compact form factors due to the slow velocity of acoustic waves, and are already used in applications ranging from timing to wireless filters. Over the past decade, novel ways i ...

EPFL2024

Impact of microwave beam scattering by density fluctuations on the electron-cyclotron power deposition profile in tokamaks

Stefano Coda, Joan Decker, Oleg Krutkin, Umesh Kumar, Jean Arthur Cazabonne

Electron-cyclotron waves are a tool commonly used in tokamaks, in particular to drive current. Their ability to drive current in a very localized manner renders them an optimal tool for MHD mode mitigation. However, such applications require high accuracy ...

IOP Publishing Ltd2024

Wigner Gaussian dynamics: Simulating the anharmonic and quantum ionic motion

Lorenzo Monacelli

The atomic motion controls important properties of materials, such as thermal transport, phase transitions, and vibrational spectra. However, simulating the ionic dynamics is exceptionally challenging when quantum fluctuations are relevant (e.g., at low te ...

AMER PHYSICAL SOC2023

Stochastic-robust planning optimization method based on tracking-economy extreme scenario tradeoff for CCHP multi-energy system

François Maréchal, Yuxuan Li

The load tracking performance of combined cooling, heating, and power multi-energy system (CCHP-MES) greatly depends on the equipment capacity configuration. And the frequent fluctuations in the source-load uncertainty puts higher demands on the load track ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Identifying Large Charge operators

Riccardo Rattazzi, Alexander Monin, Gil Badel

The Large Charge sector of Conformal Field Theory (CFT) can generically be described through a semiclassical expansion around a superfluid background. In this work, focussing on U(1) invariant Wilson-Fisher fixed points, we study the spectrum of spinning l ...

Springer Nature2023

Microscopic interplay of temperature and disorder of a one-dimensional elastic interface

Elisabeth Agoritsas, Thierry Giamarchi

Elastic interfaces display scale-invariant geometrical fluctuations at sufficiently large lengthscales. Their asymptotic static roughness then follows a power-law behavior, whose associated exponent provides a robust signature of the universality class to ...

2022

Spinon-like excitations in spin-1/2 quantum antiferromagnets

Irina Safiulina

Quantum magnetism remains a hot topic in condensed matter physics due to its complexity and possible powerful and significant applications in data storage and memory. To understand how the materials can achieve these goals, one should have a clear idea abo ...

EPFL2022

Hamiltonian reconstruction as metric for variational studies

Giuseppe Carleo

Variational approaches are among the most powerful techniques to approximately solve quantum many-body problems. These encompass both variational states based on tensor or neural networks, and parameterized quantum circuits in variational quantum eigensolv ...

2022

Engineering and characterizing nonclassical states of light in quantum optical networks

Kilian Robert Seibold

The exploration of open quantum many-body systems -systems of microscopic size exhibiting quantum coherence and interacting with their surrounding- has emerged as a key research area over the last years. The recent advances in controlling and preserving qu ...

EPFL2022

Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14-xCaxCu24O41 ladders

Henrik Moodysson Rønnow, Thorsten Schmitt, Yi Tseng

We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14-xCaxCu24O41 (SCCO) using Cu L-3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without ( ...

NATURE PORTFOLIO2022

Cavity-mediated electron-photon pairs

Tobias Kippenberg, Rui Ning Wang, Zheru Qiu, Yujia Yang, Junqiu Liu, Arslan Sajid Raja, Guanhao Huang

Quantum information, communication, and sensing rely on the generation and control of quantum correlations in complementary degrees of freedom. Free electrons coupled to photonics promise novel hybrid quantum technologies, although single-particle correlat ...

American Association for the Advancement of Science2022

Local excitations in amorphous solids

Wencheng Ji

Amorphous solids are structurally disordered. They are very common and include glasses, colloids, and granular materials, but are far less understood than crystalline solids. Key aspects of these materials are controlled by the presence of excitations in w ...

EPFL2021

Universal Aspects of Metamagnetic Transitions in Frustrated Ising Chains

Nagabhushan Ganesh Hegde

The study of magnetic frustration has been interesting due to the variety of magnetic ordering observed at low temperatures. At these temperatures thermal fluctuations become redundant and quantum fluctuations play a significant role in the determining the ...

EPFL2021

Liouvillian spectral collapse in the Scully-Lamb laser model

Fabrizio Minganti

Phase transitions of thermal systems and the laser threshold were first connected more than forty years ago. Despite the nonequilibrium nature of the laser, the Landau theory of thermal phase transitions, applied directly to the Scully-Lamb laser model (SL ...

AMER PHYSICAL SOC2021

Importance of Nuclear Quantum Effects for NMR Crystallography

Michele Ceriotti, Venkat Kapil, Edgar Albert Engel

The resolving power of solid-state nuclear magnetic resonance (NMR) crystallography depends heavily on the accuracy of computational predictions of NMR chemical shieldings of candidate structures, which are usually taken to be local minima in the potential ...

AMER CHEMICAL SOC2021

Quantum spin-liquid states in an organic magnetic layer and molecular rotor hybrid

László Forró, Bálint Náfrádi, Andrea Pisoni, Péter Szirmai, Edoardo Martino, Konstantins Mantulnikovs

The exotic properties of quantum spin liquids (QSLs) have continually been of interest since Anderson's 1973 ground-breaking idea. Geometrical frustration, quantum fluctuations, and low dimensionality are the most often evoked material's characteristics th ...

National Academy of Sciences2020

Cellular memory enhances bacterial chemotactic navigation in rugged environments

Adám Gosztolai

The response of microbes to external signals is mediated by biochemical networks with intrinsic time scales. These time scales give rise to a memory that impacts cellular behaviour. Here we study theoretically the role of cellular memory in Escherichia col ...

NATURE PUBLISHING GROUP2020

Strongly correlated Fermions strongly coupled to light

Jean-Philippe Brantut, Victor Youri Helson, Kevin Etienne Robert Roux, Hideki Konishi

Strong quantum correlations in matter are responsible for some of the most extraordinary properties of materials, from magnetism to high-temperature superconductivity, but their integration in quantum devices requires a strong, coherent coupling with photo ...

Nature Research2020

Ferrimagnetic 120 degrees magnetic structure in Cu2OSO4

Henrik Moodysson Rønnow, Arnaud Magrez, Ivica Zivkovic, Helmuth Berger, Nicola Casati, Lin Yang, Gregory Scott Tucker, Virgile Yves Favre, Romain Sibille

We report magnetic properties of a 3d(9) (Cu2+) magnetic insulator Cu2OSO4 measured on both powder and single crystal. The magnetic atoms of this compound form layers whose geometry can be described either as a system of chains coupled through dimers or as ...

AMER PHYSICAL SOC2020

Thermal origin of quasilocalized excitations in glasses

Matthieu Wyart, Thomas Willem Jan de Geus, Elisabeth Agoritsas, Wencheng Ji, Marko Popovic

Key aspects of glasses are controlled by the presence of excitations in which a group of particles can rearrange. Surprisingly, recent observations indicate that their density is dramatically reduced and their size decreases as the temperature of the super ...

2020