Publications de Alberto Beccari

Motional Sideband Asymmetry of a Solid-State Mechanical Resonator at Room Temperature

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

The motional sideband asymmetry of a mechanical oscillator interacting with a laser field can be observed when approaching the quantum ground state, where the zero-point energy of the mechanical oscillator becomes a sizable contribution to its motion. In t ...

2025

Ultrahigh-quality-factor micro- and nanomechanical resonators using dissipation dilution

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari

Mechanical resonators are widely used in sensors, transducers and optomechanical systems, where mechanical dissipation sets the ultimate limit to performance. Over the past 15 years, the quality factors in strained mechanical resonators have increased by f ...

Nature Portfolio2024

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

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

Ultralow Dissipation Mechanical Resonators for Cavity-Free Quantum Control

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

We fabricate nanomechanical resonators with Q > 109 at room temperature and show efficient optical readout of their motion. With an improved interferometer, these devices can be cooled close to the ground state without a cavity. ...

Optical Society of America2023

Strained crystalline nanomechanical resonators with quality factors above 10 billion

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

In strained mechanical resonators, the concurrence of tensile stress and geometric nonlinearity dramatically reduces dissipation. This phenomenon, called dissipation dilution, is employed in mirror suspensions of gravitational-wave interferometers and at t ...

NATURE PORTFOLIO2022

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

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

Microwave-optical transduction with intergrated gallium phospide devices

Tobias Kippenberg, Alberto Beccari

Optomechanical resonators provide a route to interconversion of microwave and optical photons for quantum interconnects. We present a platform comprising a GaP photonic crystal cavity integrated on prefabricated niobium circuits, with mechanical modes at s ...

IEEE2022

Fractal-like Mechanical Resonators with a Soft-Clamped Fundamental Mode

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

Self-similar structures occur naturally and have been employed to engineer exotic physical properties. We show that acoustic modes of a fractal-like system of tensioned strings can display increased mechanical quality factors due to the enhancement of diss ...

AMER PHYSICAL SOC2020

Thermal intermodulation noise in cavity-based measurements

Tobias Kippenberg, Dalziel Joseph Wilson, Sergey Fedorov, Alberto Beccari, Amirali Arabmoheghi

Thermal frequency fluctuations in optical cavities limit the sensitivity of precision experiments ranging from gravitational wave observatories to optical atomic clocks. Conventional modeling of these noises assumes a linear response of the optical field t ...

2020

Ultralow Dissipation Mechanical Resonators for Quantum Optomechanics

Tobias Kippenberg, Amir Hossein Ghadimi, Ryan Daniel Schilling, Dalziel Joseph Wilson, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

We demonstrate dissipation dilution engineering techniques for ultralow dissipation mechanical resonators. The Si3N4 nanobeams show quality factors (Q) as high as 800 million and Q x f exceeding 10(15) Hz-both records at room temperature. (C) 2019 The Auth ...

IEEE2019

Clamp-Tapering Increases the Quality Factor of Stressed Nanobeams

Tobias Kippenberg, Amir Hossein Ghadimi, Ryan Daniel Schilling, Dalziel Joseph Wilson, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

Stressed nanomechanical resonators are known to have exceptionally high quality factors (Q) due to the dilution of intrinsic dissipation by stress. Typically, the amount of dissipation dilution and thus the resonator Q is limited by the high mode curvature ...

AMER CHEMICAL SOC2019