Publications related to Near-Field Integration of a Si3N4 Nanobeam and a SiO2 Microcavity for Heisenberg-Limited Displacement Sensing

Magneto-Thermoelectric Transport in Graphene Quantum Dot with Strong Correlations

Disorder at etched edges of graphene quantum dots (GQD) enables random all-to-all interactions between localized charges in partially filled Landau levels, providing a potential platform to realize the Sachdev-Ye-Kitaev (SYK) model. We use quantum Hall edg ...

2024

Room-Temperature Quantum Optomechanics and Free-Electron Quantum Optics

Guanhao Huang

Quantum optics studies how photons interact with other forms of matter, the understanding of which was crucial for the development of quantum mechanics as a whole. Starting from the photoelectric effect, the quantum property of light has led to the develop ...

EPFL2024

Room-temperature quantum optomechanics using an ultralow noise cavity

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari, Guanhao Huang

At room temperature, mechanical motion driven by the quantum backaction of light has been observed only in pioneering experiments in which an optical restoring force controls the oscillator stiffness1,2. For solid-state mechanical resonators in which oscil ...

Nature Portfolio2024

Dynamical nuclear polarization for dissipation-induced entanglement in NV centers

Géraldine Haack, Shishir Khandelwal, Mayeul Sylvain Chipaux, Shashwat Kumar

We propose a practical implementation of a two-qubit entanglement engine which denotes a scheme to generate quantum correlations through purely dissipative processes. On a diamond platform, the electron spin transitions of two nitrogen-vacancy (NV) centers ...

Amer Physical Soc2023

Nanomechanical resonators with low dissipation for quantum optomechanics

Alberto Beccari

Fields of technology as diverse as microwave filter construction, characterization of material interfaces with atomic precision, and detection of gravitational waves from astronomical sources employ mechanical resonators at their core. The utility of mecha ...

EPFL2023

On double-descent in uncertainty quantification in overparametrized models

Florent Gérard Krzakala, Lenka Zdeborová, Bruno Loureiro, Lucas Andry Clarte, Bruno Loureiro

Uncertainty quantification is a central challenge in reliable and trustworthy machine learning. Naive measures such as last-layer scores are well-known to yield overconfident estimates in the context of overparametrized neural networks. Several methods, ra ...

PMLR Proceedings of Machine Learning Research2023

Universality of loop corrected soft theorems in 4d

Biswajit Sahoo

In [1], logarithmic correction to subleading soft photon and soft graviton theorems have been derived in four spacetime dimensions from the ratio of IR-finite S-matrices. This has been achieved after factoring out IR-divergent components from the tradition ...

Springer Nature2023

Ultra low quantum decoherence nano-optomechanical systems

Mohammadjafar Bereyhi

Thermal motion of a room-temperature mechanical resonator typically dominates the quantum backaction of its position measurement. This is a longstanding barrier for exploring cavity optomechanics at room temperature. In order to enter the quantum regime of ...

EPFL2022

Disentangling Light- and Temperature-Induced Thermal Effects in Colloidal Au Nanoparticles

Majed Chergui, Lijie Wang, Davood Zare

We present temperature-dependent (from room temperature to 80 degrees C) absorption spectra of Au/SiO2 core-shell nanoparticles (NPs) (core diameter: similar to 25 nm) in water in the range from 1.5 to 4.5 eV, which spans the localized surface plasmon reso ...

AMER CHEMICAL SOC2022

Gravitational causality and the self-stress of photons

Giulia Isabella, Brando Bellazzini

We study causality in gravitational systems beyond the classical limit. Using on-shell methods, we consider the 1-loop corrections from charged particles to the photon energy-momentum tensor - the self-stress - that controls the quantum interaction between ...

Springer Nature2022

Perimeter Modes of Nanomechanical Resonators Exhibit Quality Factors Exceeding 10(9) at Room Temperature

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi, Guanhao Huang

Systems with low mechanical dissipation are extensively used in precision measurements such as gravitational wave detection, atomic force microscopy, and quantum control of mechanical oscillators via optomechanics and electromechanics. The mechanical quali ...

American Physical Society2022

Guard-Ring-Free InGaAs/InP Single-Photon Avalanche Diode Based on a Novel One-Step Zn-Diffusion Technique

Claudio Bruschini, Edoardo Charbon, Myung Jae Lee, Ekin Kizilkan, Utku Karaca, Vladimir Pesic

This work presents a novel InGaAs/InP SPAD structure fabricated using a selective area growth (SAG) method. The surface topography of the selectively grown film deposited within the 70 mu m diffusion apertures is used to engineer the Zn diffusion profile t ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Hierarchical tensile structures with ultralow mechanical dissipation

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi

Structural hierarchy is found in myriad biological systems and has improved man-made structures ranging from the Eiffel tower to optical cavities. In mechanical resonators whose rigidity is provided by static tension, structural hierarchy can reduce the di ...

Nature Portfolio2022

Quantum coherent microwave-optical transduction using high-overtone bulk acoustic resonances

Tobias Kippenberg

A device capable of converting single quanta of the microwave field to the optical domain is an outstanding endeavor in the context of quantum interconnects between distant superconducting qubits, but likewise can have applications in other fields, such as ...

AMER PHYSICAL SOC2021

Non-classical photon-phonon correlations at room temperature

Santiago Tarrago Velez

With the development of quantum optics, photon correlations acquired a prominent role as a tool to test our understanding of physics, and played a key role in verifying the validity of quantum mechanics. The spatial and temporal correlations in a light fie ...

EPFL2021

Hamiltonian truncation in Anti-de Sitter spacetime

João Miguel Augusto Penedones Fernandes, Marco Meineri, Kamran Salehi Vaziri, Matthijs Jan Hogervorst

Quantum Field Theories (QFTs) in Anti-de Sitter (AdS) spacetime are often strongly coupled when the radius of AdS is large, and few methods are available to study them. In this work, we develop a Hamiltonian truncation method to compute the energy spectrum ...

Springer Nature2021

Strong Coupling of Antiferromagnetic Resonance with Subterahertz Cavity Fields

Jean-Philippe Ansermet, Haiming Yu, Marcin Bialek

Strong coupling of electromagnetic cavity fields with antiferromagnetic spin waves in hematite (alpha-Fe2O3) is achieved above room temperature. A cube of hematite is placed in a metallic tube and the transmission is measured, using a continuous-wave terah ...

American Physical Society (APS)2021

Quantum Measurement of Mechanical Motion close to the Standard Quantum Limit

Liu Qiu

In quantum mechanics, the Heisenberg uncertainty principle places a fundamental limit in the measurement precision for certain pairs of physical quantities, such as position and momentum, time and energy or amplitude and phase. Due to the Heisenberg uncert ...

EPFL2020

Nuclear Quantum Effects: Fast and Accurate

Venkat Kapil

Atomistic simulations are a bottom up approach that predict properties of materials by modelling the quantum mechanical behaviour of all electrons and nuclei present in a system. These simulations, however, routinely assume nuclei to be classical particles ...

EPFL2020

Accurate Description of Nuclear Quantum Effects with High-Order Perturbed Path Integrals (HOPPI)

Michele Ceriotti, Venkat Kapil

Imaginary time path-integral (PI) simulations that account for nuclear quantum effects (NQE) beyond the harmonic approximation are increasingly employed together with modern electronic-structure calculations. Existing PI methods are applicable to molecules ...

AMER CHEMICAL SOC2020