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Optical self-cooling of a membrane oscillator in a cavity optomechanical experiment at room temperature

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Physical Review A 2023年第6期108卷 063508-063508页

作者： P. Vezio M. Bonaldi A. Borrielli F. Marino B. Morana P. M. Sarro E. Serra F. Marin Dipartimento di Fisica e Astronomia Università di Firenze via Sansone 1 I-50019 Sesto Fiorentino (FI) Italy Nanoscience-Trento-FBK Division Institute of Materials for Electronics and Magnetism I-38123 Povo Trento Italy Trento Institute for Fundamental Physics and Application Istituto Nazionale di Fisica Nucleare I-38123 Povo Trento Italy CNR-INO largo Enrico Fermi 6 I-50125 Firenze Italy INFN Sezione di Firenze via Sansone 1 I-50019 Sesto Fiorentino (FI) Italy Department of Microelectronics and Computer Engineering/ECTM/DIMES Delft University of Technology Feldmanweg 17 NL-2628 CT Delft The Netherlands European Laboratory for Non-Linear Spectroscopy via Carrara 1 I-50019 Sesto Fiorentino (FI) Italy

Thermal noise is a major obstacle to observing quantum behavior in macroscopic systems. To mitigate its effect, quantum optomechanical experiments are typically performed in a cryogenic environment. However, this condition represents a considerable complication in the transition from fundamental research to quantum technology applications. It is therefore interesting to explore the possibility of achieving the quantum regime in room-temperature experiments. In this work we test the limits of sideband-cooling vibration modes of a SiN membrane in a cavity optomechanical experiment. We obtain an effective temperature of a few millikelvins, corresponding to a phononic occupation number of around 100. We show that further cooling is prevented by the excess classical noise of our laser source, and we outline the road toward the achievement of ground state cooling.

关键词： Optomechanics

The construction and characterization of MgO transmission dynodes

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arXiv 2023年

作者： Chan, H.W. Prodanović, V. Theulings, A.M.M.G. Tao, S. Smedley, J. Hagen, C.W. Sarro, P.M. Graaf, H.V.D. Science Park 105 Amsterdam1098 XG Netherlands Faculty of Electrical Engineering Mathematics and Computer Science Department of Microelectronics ECTM Delft University of Technology Feldmannweg 17 Delft2628 CT Netherlands Faculty of Applied Sciences Department of Imaging Physics Delft University of Technology Lorentzweg 1 Delft2628 CJ Netherlands Department of Applied Physics Eindhoven University of Technology Eindhoven5600 MB Netherlands SLAC National Accelerator Laboratory Stanford University 2575 Sand Hill Road Menlo ParkCA94025 United States

In this work we demonstrate that ultra-thin (5 and 15 nm) MgO transmission dynodes with sufficient high transmission electron yield (TEY) can be constructed. These transmission dynodes act as electron amplification stages in a novel vacuum electron multiplier: the Timed Photon Counter. The ultra-thin membranes with a diameter of 30 µm are arranged in a square 64-by-64-array. The TEY was determined with a scanning electron microscope using primary electrons with primary energies of 0.75 - 5 keV. The method allows a TEY map of the surface to be made while simultaneously imaging the surface. The TEY of individual membranes can be extracted from the TEY map. An averaged maximum TEY of 4.6 ± 0.2 was achieved by using 1.35 keV primary electrons on a TiN/MgO bi-layer membrane with a layer thickness of 2 and 5 nm, respectively. The TiN/MgO membrane with a layer thickness of 2 and 15 nm, respectively, has a maximum TEY of 3.3 ± 0.1 (2.35 keV). Furthermore, the effect of the electric field strength on transmission (secondary) electron emission was investigated by placing the emission surface of a transmission dynode in close proximity to a planar collector. By increasing the electric potential between the transmission dynode and the collector, from -50 V to -100 V, the averaged maximum TEY improved from 4.6 ± 0.2 to 5.0 ± 0.3 at a primary energy of 1.35 keV with an upper limit of 5.5 on one of the membranes. Copyright © 2023, The Authors. All rights reserved.

关键词： Electrons

Active feedback cooling of a SiN membrane resonator by electrostatic actuation

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arXiv 2021年

作者： Borrielli, Antonio Bonaldi, Michele Serra, Enrico Sarro, Pasqualina Maria Morana, Bruno Institute of Materials for Electronics and Magnetism IMEM-CNR Trento unit c/o Fondazione Bruno Kessler Via alla Cascata 56/C Povo TrentoIT-38123 Italy Dept. of Microelectronics and Computer Engineering ECTM DIMES Delft University of Technology Feldmanweg 17 Delft2628 CT Netherlands Trento Institute for Fundamental Physics and Application Povo Trento38123 Italy

Feedback-based control techniques are useful tools in precision measurements as they allow to actively shape the mechanical response of high quality factor oscillators used in force detection measurements. In this paper we implement a feedback technique on a high-stress low-loss SiN membrane resonator, exploiting the charges trapped on the dielectric membrane. A properly delayed feedback force (dissipative feedback) enables the narrowing of the thermomechanical displacement variance in a similar manner to the cooling of the normal mechanical mode down to an effective temperature Te f f. In the experiment here reported we started from room temperature and gradually increasing the feedback gain we were able to cool down the first normal mode of the resonator to a minimum temperature of about 124mK. This limit is imposed by our experimental set-up and in particular by the the injection of the read-out noise into the feedback. We discuss the implementation details and possible improvements to the technique. Copyright © 2021, The Authors. All rights reserved.

关键词： Resonators

Low Noise Opto-Electro-Mechanical Modulator for RF-to-Optical Transduction in Quantum Communications

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arXiv 2023年

作者： Bonaldi, Michele Borrielli, Antonio Di Giuseppe, Giovanni Malossi, Nicola Morana, Bruno Natali, Riccardo Piergentili, Paolo Sarro, Pasqualina Maria Serra, Enrico Vitali, David Institute of Materials for Electronics and Magnetism Nanoscience-Trento-FBK Division TN Povo38123 Italy Istituto Nazionale di Fisica Nucleare TIFPA TN Povo38123 Italy Physics Division School of Science and Technology University of Camerino MC Camerino62032 Italy INFN Sezione di Perugia PG Perugia06123 Italy Department of Microelectronics and Computer Engineering ECTM Delft University of Technology Feldmanweg 17 Delft2628 CT Netherlands CNR-INO L.go Enrico Fermi 6 FI Firenze50125 Italy

In this work, we present an Opto-Electro-Mechanical Modulator (OEMM) for RF-to-optical transduction realized via an ultra-coherent nanomembrane resonator capacitively coupled to an rf injection circuit made of a microfabricated read-out able to improve the electro-optomechanical interaction. This device configuration can be embedded in a Fabry–Perot cavity for electromagnetic cooling of the LC circuit in a dilution refrigerator exploiting the opto-electro-mechanical interaction. To this aim, an optically measured steady-state frequency shift of 380 Hz was seen with a polarization voltage of 30 V and a Q-factor of the assembled device above 106 at room temperature. The rf-sputtered titanium nitride layer can be made superconductive to develop efficient quantum transducers. Copyright © 2023, The Authors. All rights reserved.

关键词： Hybrid systems

Sympathetic cooling of a radio-frequency LC circuit to its ground state in an optoelectromechanical system

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Physical Review A 2021年第3期103卷 033516-033516页

作者： Nicola Malossi Paolo Piergentili Jie Li Enrico Serra Riccardo Natali Giovanni Di Giuseppe David Vitali Physics Division School of Science and Technology University of Camerino I-62032 Camerino (MC) Italy INFN Sezione di Perugia via A. Pascoli I-06123 Perugia Italy Kavli Institute of Nanoscience Department of Quantum Nanoscience Delft University of Technology 2628CJ Delft The Netherlands Zhejiang Province Key Laboratory of Quantum Technology and Device Department of Physics and State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China Institute of Materials for Electronics and Magnetism Nanoscience-Trento-FBK Division I-38123 Povo Trento Italy INFN Trento Institute for Fundamental Physics and Application I-38123 Povo Trento Italy Department of Microelectronics and Computer Engineering/ECTM/DIMES Delft University of Technology Feldmanweg 17 2628 CT Delft The Netherlands CNR-INO Largo Enrico Fermi 6 I-50125 Firenze Italy

We present a complete theory for laser cooling of a macroscopic radio-frequency LC electrical circuit by means of an optoelectromechanical system, consisting of an optical cavity dispersively coupled to a nanomechanical oscillator, which is in turn capacitively coupled to the LC circuit of interest. The driven optical cavity cools the mechanical resonator, which in turn sympathetically cools the LC circuit. We determine the optimal parameter regime where the LC resonator can be cooled down to its quantum ground state, which requires a large optomechanical cooperativity, and a larger electromechanical cooperativity. Moreover, comparable optomechanical and electromechanical coupling rates are preferable for reaching the quantum ground state.

关键词： Optomechanics

Secondary electron emission from multi-layered TiN/Al2O3 transmission dynodes

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arXiv 2020年

作者： Chan, Hong Wah Prodanović, V. Theulings, A.M.M.G. Hagen, C.W. Sarro, P.M. v.d Graaf, H. Science Park 105 Amsterdam1098 XG Netherlands Faculty of Electrical Engineering Mathematics and Computer science Department of Microelectronics ECTM Feldmannweg 17 Delft2628 CT Netherlands Faculty of applied sciences Department of Imaging Physics Delft University of Technology Lorentzweg 1 Delft2628 CJ Netherlands

The (secondary) electron emission from multilayered Al2O3/TiN membranes has been investigated with a hemispherical collector system in a scanning electron microscope for electrons with energies between 0.3 and 10 keV. These ultra-thin membranes are designed to function as transmission dynodes in novel vacuum electron multipliers. Two different types, a bi-layer and a tri-layer, have been manufactured by means of atomic-layer deposition (ALD) of aluminum oxide and sputtering of titanium nitride. The reflection and transmission electron yield (ϭR, ϭT ) have been measured for both types of membranes. In comparison, the tri-layer membranes outperformed the bi-layer membranes in terms of transmission electron yield for films with the same effective thickness. The highest transmission electron yield was measured on an Al2O3/TiN/Al2O3 film with layer thicknesses of 5/2.5/5 nm, which had a maximum transmission electron yield ϭTmax (E0) of 3.1(1.55 keV). Furthermore, the bi-layer membranes have been investigated more in-depth by performing an additional measurement using a positive sample bias to separate the transmitted fraction ηT and the transmission secondary electron yield ℘T. The transmitted fraction was used to determine the transmission parameter P, which characterizes the interaction of primary electrons (PEs) in thin films. The transmission secondary electron yield was used to compare the energy transfer of PEs in films with different thicknesses. Copyright © 2020, The Authors. All rights reserved.

关键词： Alumina

Ultra-thin corrugated metamaterial film as large-area transmission dynode

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arXiv 2020年

作者： Chan, H.W. Prodanović, V. Theulings, A.M.M.G. Bruggencate, T. ten Hagen, C.W. Sarro, P.M. van der Graaf, H. Science Park 105 Amsterdam1098 XG Netherlands Faculty of Electrical Engineering Mathematics and Computer science Department of microelectronics ECTM Feldmannweg 17 Delft2628 CT Netherlands Faculty of applied sciences Department of Imaging Physics Delft University of Technology Lorentzweg 1. Delft2628 CJ Netherlands

Large-area transmission dynodes were fabricated by depositing an ultra-thin continuous film on a silicon wafer with a 3-dimensional pattern. After removing the silicon, a corrugated membrane with enhanced mechanical properties was formed. Mechanical metamaterials, such as this corrugated membrane, are engineered to improve its strength and robustness, which allows it to span a larger surface in comparison to flat membranes while the film thickness remains constant. The ultra-thin film consists of three layers (Al2O3/TiN/Al2O3) and is deposited by atomic layer deposition (ALD). The encapsulated TiN layer provides in-plane conductivity, which is needed to sustain secondary electron emission. Two types of corrugated membranes were fabricated: a hexagonal honeycomb and an octagonal pattern. The latter was designed to match the square pitch of a CMOS pixel chip. The transmission secondary electron yield was determined with a collector-based method using a scanning electron microscope. The highest transmission electron yield was measured on a membrane with an octagonal pattern. A yield of 2.15 was achieved for 3.15 keV incident electrons for an Al2O3/TiN/Al2O3 tri-layer film with layer thicknesses of 10/5/15 nm. The variation in yield across the surface of the corrugated membrane was determined by constructing a yield map. The active surface for transmission secondary electron emission is near 100%, i.e. a primary electron generates transmission secondary electrons regardless of the point of impact on the corrugated membrane. Copyright © 2020, The Authors. All rights reserved.

关键词： Silicon wafers

Measurement of the transmission secondary electron yield of nanometer-thick films in a prototype Timed Photon Counter

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arXiv 2020年

作者： van der Reep, Tom H.A. Looman, B. Chan, H.W. Hagen, C.W. van der Graaf, H. Science Park 105 Amsterdam1098 XG Netherlands Faculty of applied sciences Department of Imaging Physics Delft University of Technology Lorentzweg 1 Delft2628 CJ Netherlands Faculty of electrical engineering mathematics and computer science Department of Microelectronics/ECTM Delft University of Technology Feldmanweg 17 Delft2628 CT Netherlands

We measure the transmission secondary electron yield of nanometer-thick Al2O3/TiN/Al2O3 films using a prototype version of a Timed Photon Counter (TiPC). We discuss the method to measure the yield extensively. The yield is then measured as a function of landing energy between 1.2 and 1.8 keV and found to be in the range of 0.1 (1.2 keV) to 0.9 (1.8 keV). These results are in agreement to data obtained by a different, independent method. We therefore conclude that the prototype TiPC is able to characterise the thin films in terms of transmission secondary electron yield. Additionally, observed features which are unrelated to the yield determination are interpreted. Copyright © 2020, The Authors. All rights reserved.

关键词： Aluminum oxide

Quantum motion of a squeezed mechanical oscillator attained via a optomechanical experiment

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arXiv 2020年

作者： Vezio, P. Chowdhury, A. Bonaldi, M. Borrielli, A. Marino, F. Morana, B. Prodi, G.A. Sarro, P.M. Serra, E. Marin, F. I-50019 Italy CNR-INO L.go Enrico Fermi 6 FirenzeI-50125 Italy Institute of Materials for Electronics and Magnetism Nanoscience-Trento-FBK Division Povo Trento38123 Italy Trento Institute for Fundamental Physics and Application Povo TrentoI-38123 Italy INFN Sezione di Firenze Dept. of Microelectronics and Computer Engineering ECTM/DIMES Delft University of Technology Feldmanweg 17 Delft2628 CT Netherlands Dipartimento di Matematica Università di Trento Povo TrentoI-38123 Italy I-50019 Italy

We experimentally investigate a mechanical squeezed state realized in a parametrically-modulated membrane resonator embedded in an optical cavity. We demonstrate that a quantum characteristic of the squeezed dynamics can be revealed and quantified even in a moderately warm oscillator, through the analysis of motional sidebands. We provide a theoretical framework for quantitatively interpreting the observations and present an extended comparison with the experiment. A notable result is that the spectral shape of each motional sideband provides a clear signature of a quantum mechanical squeezed state without the necessity of absolute calibrations, in particular in the regime where residual fluctuations in the squeezed quadrature are reduced below the zero-point level. Copyright © 2020, The Authors. All rights reserved.

关键词： Quantum optics