Publications related to Perpetual motion

Room-temperature quantum optomechanics using an ultralow noise cavity

Tobias Kippenberg, Alberto Beccari, Nils Johan Engelsen, 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

Sparse autoregressive neural networks for classical spin systems

Giuseppe Carleo, Dian Wu, Indaco Biazzo

Efficient sampling and approximation of Boltzmann distributions involving large sets of binary variables, or spins, are pivotal in diverse scientific fields even beyond physics. Recent advances in generative neural networks have significantly impacted this ...

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

Information Theory in Transmembrane Transport

Solange Marie Flatt

The past decades have seen the advent of information theory in various fields, from quantum physics to cosmology. At an intermediary scale between atomic and cosmological scales are biological systems and in particular the cell, as a constitutive element o ...

EPFL2023

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

Prospective motion correction in kidney MRI using FID navigators

Tobias Kober

Purpose Abdominal MRI scans may require breath-holding to prevent image quality degradation, which can be challenging for patients, especially children. In this study, we evaluate whether FID navigators can be used to measure and correct for motion prospec ...

WILEY2022

A High Efficiency Pneumatic Drive System Using Vane-Type Semi-Rotary Actuators

Alfred Rufer

A compressed air driven generator is proposed, where the pneumatic energy is converted into mechanical energy using two vane-type rotational actuators. The use of a second actuator with a higher displacement in order to produce a thermodynamic expansion al ...

UNIV NIS2021

Molecular motor crossing the frontier of classical to quantum tunneling motion

Harald Brune, Roland Widmer, Jan Prinz, Samuel Thomas Stolz

The reliability by which molecular motor proteins convert undirected energy input into directed motion or transport has inspired the design of innumerable artificial molecular motors. We have realized and investigated an artificial molecular motor applying ...

National Academy of Sciences2020

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

Development of collapse-consistent loading protocols for experimental testing of steel columns

Dimitrios Lignos

In order to effectively utilize results from quasi-static cyclic testing on structural components for the earthquake-induced collapse risk quantification of structures, the need exists to establish collapse-consistent loading protocols representing the asy ...

2020

Laser Cooling of a Nanomechanical Oscillator to Its Zero-Point Energy

Tobias Kippenberg, Liu Qiu, Itay Shomroni

Optomechanical systems in the well-resolved-sideband regime are ideal for studying a myriad of quantum phenomena with mechanical systems, including backaction-evading measurements, mechanical squeezing, and nonclassical states generation. For these experim ...

AMER PHYSICAL SOC2020

Unraveling intrinsic correlation effects with angle-resolved photoemission spectroscopy

Marco Vanzini, Vladimir N. Strocov

Interaction effects can change materials properties in intriguing ways, and they have, in general, a huge impact on electronic spectra. In particular, satellites in photoemission spectra are pure many-body effects, and their study is of increasing interest ...

National Academy of Sciences2020

A Molecular Dual Pump

Cristian Pezzato

Artificial molecular machines (AMMs) built from mechanically interlocked molecules (MIMs) can use energy ratchets to control the unidirectional motion of their component parts. These energy ratchets are operated by the alteration of kinetic barriers and th ...

AMER CHEMICAL SOC2019

Two-Tone Optomechanical Instability and Its Fundamental Implications for Backaction-Evading Measurements

Tobias Kippenberg, Amir Youssefi, Liu Qiu, Itay Shomroni

While quantum mechanics imposes a fundamental limit on the precision of interferometric measurementsof mechanical motion due to measurement backaction, the nonlinear nature of the coupling also leads toparametric instabilities that place practical limits o ...

American Physical Society2019

Improving the arm-hand coordination in neuroprosthetics control with prior information from muscle activity

Iason Batzianoulis

Humans use their hands mainly for grasping and manipulating objects, performing simple and dexterous tasks. The loss of a hand may significantly affect one's working status and independence in daily life. A restoration of the grasping ability is important ...

EPFL2019

Decoding the Grasping Intention from Electromyography during Reaching Motions

Aude Billard, Iason Batzianoulis, Nili Eliana Krausz

Background: Active upper-limb prostheses are used to restore important hand functionalities, such as grasping. In conventional approaches, a pattern recognition system is trained over a number of static grasping gestures. However, training a classifier in ...

BioMed Central2018

Ultra-coherent nano-mechanical resonators for quantum optomechanics at room temperature

Amir Hossein Ghadimi

Mechanical oscillators are among the most important scientific tools in the modern physics. From the pioneering experiments in 18th by founding fathers of modern physics such as Newton, Hooke and Cavendish to the ground braking experiments in the 21th cent ...

EPFL2018

Evidence for structural damping in a high-stress silicon nitride nanobeam and its implications for quantum optomechanics

Tobias Kippenberg, Dalziel Joseph Wilson, Sergey Fedorov, Ryan Daniel Schilling, Vivishek Sudhir, Hendrik Schütz

We resolve the thermal motion of a high-stress silicon nitride nanobeam at frequencies far below its fundamental flexural resonance (3.4 MHz) using cavity-enhanced optical interferometry. Over two decades, the displacement spectrum is well-modeled by that ...

2018

A dissipative quantum reservoir for microwave light using a mechanical oscillator

Tobias Kippenberg, Nathan Rafaël Bernier, László Dániel Tóth

Isolation of a system from its environment is often desirable, from precision measurements to control of individual quantum systems; however, dissipation can also be a useful resource. Remarkably, engineered dissipation enables the preparation of quantum s ...

2017

Penciling a triboelectric nanogenerator on paper for autonomous power MEMS applications

Jürgen Brugger, Xiao Sheng Zhang

Triboelectric nanogenerator (TENG) has proven to be a robust power source to efficiently convert ambient mechanical energy into electricity. It experienced substantial growth in the past years owing to its appealing features that make it superior than othe ...

Elsevier Science Bv2017