Pub Date : 2021-08-30DOI: 10.21203/RS.3.RS-855578/V1
D. Moss
We demonstrate a photonic radio frequency (RF) transversal filter based on an integrated optical micro-comb source featuring a record low free spectral range of 49 GHz yielding 80 micro-comb lines across the C-band. This record-high number of taps, or wavelengths for the transversal filter results in significantly increased performance including a QRF factor more than four times higher than previous results. Further, by employing both positive and negative taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using Gaussian apodization, together with a tunable centre frequency covering the RF spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically adjustable filter shapes. Our experimental results match well with theory, showing that our transversal filter is a competitive solution to implement advanced adaptive RF filters with broad operational bandwidths, high frequency selectivity, high reconfigurability, and potentially reduced cost and footprint. This approach is promising for applications in modern radar and communications systems.
{"title":"High performance photonic microwave filters based on a 50GHz FSR optical soliton crystal Kerr micro-comb","authors":"D. Moss","doi":"10.21203/RS.3.RS-855578/V1","DOIUrl":"https://doi.org/10.21203/RS.3.RS-855578/V1","url":null,"abstract":"\u0000 We demonstrate a photonic radio frequency (RF) transversal filter based on an integrated optical micro-comb source featuring a record low free spectral range of 49 GHz yielding 80 micro-comb lines across the C-band. This record-high number of taps, or wavelengths for the transversal filter results in significantly increased performance including a QRF factor more than four times higher than previous results. Further, by employing both positive and negative taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using Gaussian apodization, together with a tunable centre frequency covering the RF spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically adjustable filter shapes. Our experimental results match well with theory, showing that our transversal filter is a competitive solution to implement advanced adaptive RF filters with broad operational bandwidths, high frequency selectivity, high reconfigurability, and potentially reduced cost and footprint. This approach is promising for applications in modern radar and communications systems.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82661836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report world record high data transmission over standard optical fiber from a single optical source. We achieve a line rate of 44.2 Terabits per second (Tb/s) employing only the C-band at 1550nm, resulting in a spectral efficiency of 10.4 bits/s/Hz. We use a new and powerful class of micro-comb called soliton crystals that exhibit robust operation and stable generation as well as a high intrinsic efficiency that, together with an extremely low spacing of 48.9 GHz enables a very high coherent data modulation format of 64 QAM. We achieve error free transmission across 75 km of standard optical fiber in the lab and over a field trial with a metropolitan optical fiber network. This work demonstrates the ability of optical micro-combs to exceed other approaches in performance for the most demanding practical optical communications applications.
{"title":"Ultra-high bandwidth fiber-optic data transmission with a single chip source","authors":"D. Moss","doi":"10.1117/12.2584014","DOIUrl":"https://doi.org/10.1117/12.2584014","url":null,"abstract":"\u0000 We report world record high data transmission over standard optical fiber from a single optical source. We achieve a line rate of 44.2 Terabits per second (Tb/s) employing only the C-band at 1550nm, resulting in a spectral efficiency of 10.4 bits/s/Hz. We use a new and powerful class of micro-comb called soliton crystals that exhibit robust operation and stable generation as well as a high intrinsic efficiency that, together with an extremely low spacing of 48.9 GHz enables a very high coherent data modulation format of 64 QAM. We achieve error free transmission across 75 km of standard optical fiber in the lab and over a field trial with a metropolitan optical fiber network. This work demonstrates the ability of optical micro-combs to exceed other approaches in performance for the most demanding practical optical communications applications.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"C-25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84429637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-23DOI: 10.21203/RS.3.RS-414115/V1
Urs A. T. Hofmann, Sergio P'erez-L'opez, H. Estrada, D. Razansky
The authors have requested that this preprint be removed from Research Square.
作者已经要求从研究广场上删除这个预印本。
{"title":"High order pulse-echo (HOPE) ultrasound","authors":"Urs A. T. Hofmann, Sergio P'erez-L'opez, H. Estrada, D. Razansky","doi":"10.21203/RS.3.RS-414115/V1","DOIUrl":"https://doi.org/10.21203/RS.3.RS-414115/V1","url":null,"abstract":"\u0000 The authors have requested that this preprint be removed from Research Square.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83790816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-30DOI: 10.17028/RD.LBORO.14588484.V1
H. Kansara, G. Koh, M. Varghese, John Z. X. Luk, E. Gómez, Siddhant Kumar, Han Zhang, Emilio Mart'inez-Paneda, Wei Tan
The project aims to explore a novel way to design and produce cellular materials with good energy absorption and recoverability properties. Spinodoid structures offer an alternative to engineering structures such as honeycombs and foam with scalability ensuring microscale benefits are reaped on a larger scale. Various materials and topologies have been utilised for numerical modeling and prototyping through additive manufacturing. Each design was evaluated using finite element modelling. Initial results from numerical models show anisotropic structures achieving high energy absorption efficiency. Through data-driven optimisation, results show a peak energy absorption value of 5.34 MJ/m3 for anisotropic columnar structure. A physics-informed biased grid-search optimisation is faster due to parameters being explored in parallel. To validate the numerical model, compressive tests on various prototypes were conducted.
{"title":"Data-driven modelling of scalable spinodoid structures for energy absorption","authors":"H. Kansara, G. Koh, M. Varghese, John Z. X. Luk, E. Gómez, Siddhant Kumar, Han Zhang, Emilio Mart'inez-Paneda, Wei Tan","doi":"10.17028/RD.LBORO.14588484.V1","DOIUrl":"https://doi.org/10.17028/RD.LBORO.14588484.V1","url":null,"abstract":"The project aims to explore a novel way to design and produce cellular materials with good energy\u0000absorption and recoverability properties. Spinodoid structures offer an alternative to engineering\u0000structures such as honeycombs and foam with scalability ensuring microscale benefits are reaped\u0000on a larger scale. Various materials and topologies have been utilised for numerical modeling\u0000and prototyping through additive manufacturing. Each design was evaluated using finite element\u0000modelling. Initial results from numerical models show anisotropic structures achieving high energy\u0000absorption efficiency. Through data-driven optimisation, results show a peak energy absorption\u0000value of 5.34 MJ/m3\u0000for anisotropic columnar structure. A physics-informed biased grid-search\u0000optimisation is faster due to parameters being explored in parallel. To validate the numerical\u0000model, compressive tests on various prototypes were conducted.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87389767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-05DOI: 10.21203/RS.3.RS-188025/V1
R. M. Abraham-Ekeroth
Surface plasmons with MHz-GHz energies are predicted by using milliparticles made of metamaterials that behave like metals in the radiofrequency range. In this work, the so-called Radioplasmonics is exploited to design scatterers embedded in different realistic media with tunable absorption or scattering properties. High-quality scattering/absorption based on plasmon excitation is demonstrated through a few simple examples, useful to build antennas with better performance than conventional ones. Systems embedded in absorbing media as saline solutions or biological tissues are also considered to improve biomedical applications and contribute with real-time, in-vivo monitoring tools in body tissues. In this regard, any possible implementation is criticized by calculating the radiofrequency heating with full thermal simulations. As proof of the versatility offered by radioplasmonic systems, plasmon “hybridization” is used to enhance near-fields to unprecedented values or to tune resonances as in optical spectra, minimizing the heating effects. Finally, a monitorable drug-delivery in human tissue is illustrated with a hypothetical example. This study has remarkable consequences on the conception of plasmonics at macroscales. The recently-developed concept of “spoof” plasmons achieved by complicated structures is simplified in Radioplasmonics since bulk materials with elemental geometries are considered.
{"title":"Radioplasmonics: design of plasmonic milli-particles in air and absorbing media for antenna communication and human-body in-vivo applications.","authors":"R. M. Abraham-Ekeroth","doi":"10.21203/RS.3.RS-188025/V1","DOIUrl":"https://doi.org/10.21203/RS.3.RS-188025/V1","url":null,"abstract":"\u0000 Surface plasmons with MHz-GHz energies are predicted by using milliparticles made of metamaterials that behave like metals in the radiofrequency range. In this work, the so-called Radioplasmonics is exploited to design scatterers embedded in different realistic media with tunable absorption or scattering properties. High-quality scattering/absorption based on plasmon excitation is demonstrated through a few simple examples, useful to build antennas with better performance than conventional ones. Systems embedded in absorbing media as saline solutions or biological tissues are also considered to improve biomedical applications and contribute with real-time, in-vivo monitoring tools in body tissues. In this regard, any possible implementation is criticized by calculating the radiofrequency heating with full thermal simulations. As proof of the versatility offered by radioplasmonic systems, plasmon “hybridization” is used to enhance near-fields to unprecedented values or to tune resonances as in optical spectra, minimizing the heating effects. Finally, a monitorable drug-delivery in human tissue is illustrated with a hypothetical example.\u0000This study has remarkable consequences on the conception of plasmonics at macroscales. The recently-developed concept of “spoof” plasmons achieved by complicated structures is simplified in Radioplasmonics since bulk materials with elemental geometries are considered.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"169 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85397699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Gobet, P. Barberet, L. Courtois, G. Devès, J. Gardelle, S. Leblanc, L. Plawinski, H. Seznec
A compact low-energy and high-intensity X-ray source for radiation biology applications is presented. A laser-induced plasma moves inside a 30 kV diode and produces a beam of 10$^{14}$ electrons at the anode location. An aluminum foil converts a part of the energy of these electrons into X-ray photons which are characterized using filtered imaging plates. The dose that would be deposited by these X-ray photons in C. elegans larvae is calculated from Geant4 simulations. It can be set to a value ranging between 10 $mu$Gy and 10 mGy per laser shot by simply changing the aluminum foil thickness and the diode voltage. Therefore, this versatile and compact X-ray source opens a new path to explore the radiation effects induced by dose rates varying over several orders of magnitude.
{"title":"X-ray photons produced from a plasma-cathode electron beam for radiation biology applications","authors":"F. Gobet, P. Barberet, L. Courtois, G. Devès, J. Gardelle, S. Leblanc, L. Plawinski, H. Seznec","doi":"10.1063/5.0036284","DOIUrl":"https://doi.org/10.1063/5.0036284","url":null,"abstract":"A compact low-energy and high-intensity X-ray source for radiation biology applications is presented. A laser-induced plasma moves inside a 30 kV diode and produces a beam of 10$^{14}$ electrons at the anode location. An aluminum foil converts a part of the energy of these electrons into X-ray photons which are characterized using filtered imaging plates. The dose that would be deposited by these X-ray photons in C. elegans larvae is calculated from Geant4 simulations. It can be set to a value ranging between 10 $mu$Gy and 10 mGy per laser shot by simply changing the aluminum foil thickness and the diode voltage. Therefore, this versatile and compact X-ray source opens a new path to explore the radiation effects induced by dose rates varying over several orders of magnitude.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"87 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80007322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-29DOI: 10.23919/MWP48676.2020.9314409
Xingyuan Xu, M. Tan, D. Moss
Optical artificial neural networks (ONNs) have significant potential for ultra-high computing speed and energy efficiency. We report a new approach to ONNs based on integrated Kerr micro-combs that is programmable, highly scalable and capable of reaching ultra-high speeds, demonstrating the building block of the ONN, a single neuron perceptron, by mapping synapses onto 49 wavelengths to achieve a single-unit throughput of 11.9 Giga-OPS at 8 bits per OP, or 95.2 Gbps. We test the perceptron on handwritten-digit recognition and cancer-cell detection, achieving over 90% and 85% accuracy, respectively. By scaling the perceptron to a deep learning network using off the shelf telecom technology we can achieve high throughput operation for matrix multiplication for real-time massive data processing.
{"title":"Soliton crystal Kerr microcombs for high-speed, scalable optical neural networks at 10 GigaOPs/s","authors":"Xingyuan Xu, M. Tan, D. Moss","doi":"10.23919/MWP48676.2020.9314409","DOIUrl":"https://doi.org/10.23919/MWP48676.2020.9314409","url":null,"abstract":"Optical artificial neural networks (ONNs) have significant potential for ultra-high computing speed and energy efficiency. We report a new approach to ONNs based on integrated Kerr micro-combs that is programmable, highly scalable and capable of reaching ultra-high speeds, demonstrating the building block of the ONN, a single neuron perceptron, by mapping synapses onto 49 wavelengths to achieve a single-unit throughput of 11.9 Giga-OPS at 8 bits per OP, or 95.2 Gbps. We test the perceptron on handwritten-digit recognition and cancer-cell detection, achieving over 90% and 85% accuracy, respectively. By scaling the perceptron to a deep learning network using off the shelf telecom technology we can achieve high throughput operation for matrix multiplication for real-time massive data processing.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90451728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Dang, J. Hawecker, E. Rongione, G. B. Baez Flores, D. To, J. Rojas-Sánchez, H. Nong, J. Mangeney, J. Tignon, F. Godel, S. Collin, P. Sénéor, M. Bibes, A. Fert, M. Anane, J. George, L. Vila, M. Cosset-Cheneau, D. Dolfi, R. Lebrun, P. Bortolotti, K. Belashchenko, S. Dhillon, H. Jaffrès
Spintronic structures are extensively investigated for their spin orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-transition metal interfaces due to their inverse spin-Hall effect properties. In particular the intrinsic inverse spin Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques -- ultrafast THz time domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping measurements in the GHz regime in the steady state -- to determine the role played by the material properties, resistivities, spin transmission at metallic interfaces and spin-flip rates. These measurements show the correspondence between the THz time domain spectroscopy and ferromagnetic spin-pumping for the different set of samples in term of the spin mixing conductance. The latter quantity is a critical parameter, determining the strength of the THz emission from spintronic interfaces. This is further supported by ab-initio calculations, simulations and analysis of the spin-diffusion and spin relaxation of carriers within the multilayers in the time domain, permitting to determine the main trends and the role of spin transmission at interfaces. This work illustrates that time domain spectroscopy for spin-based THz emission is a powerful technique to probe spin-dynamics at active spintronic interfaces and to extract key material properties for spin-charge conversion.
{"title":"Ultrafast spin-currents and charge conversion at 3d-5d interfaces probed by time-domain terahertz spectroscopy","authors":"T. Dang, J. Hawecker, E. Rongione, G. B. Baez Flores, D. To, J. Rojas-Sánchez, H. Nong, J. Mangeney, J. Tignon, F. Godel, S. Collin, P. Sénéor, M. Bibes, A. Fert, M. Anane, J. George, L. Vila, M. Cosset-Cheneau, D. Dolfi, R. Lebrun, P. Bortolotti, K. Belashchenko, S. Dhillon, H. Jaffrès","doi":"10.1063/5.0022369","DOIUrl":"https://doi.org/10.1063/5.0022369","url":null,"abstract":"Spintronic structures are extensively investigated for their spin orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-transition metal interfaces due to their inverse spin-Hall effect properties. In particular the intrinsic inverse spin Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques -- ultrafast THz time domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping measurements in the GHz regime in the steady state -- to determine the role played by the material properties, resistivities, spin transmission at metallic interfaces and spin-flip rates. These measurements show the correspondence between the THz time domain spectroscopy and ferromagnetic spin-pumping for the different set of samples in term of the spin mixing conductance. The latter quantity is a critical parameter, determining the strength of the THz emission from spintronic interfaces. This is further supported by ab-initio calculations, simulations and analysis of the spin-diffusion and spin relaxation of carriers within the multilayers in the time domain, permitting to determine the main trends and the role of spin transmission at interfaces. This work illustrates that time domain spectroscopy for spin-based THz emission is a powerful technique to probe spin-dynamics at active spintronic interfaces and to extract key material properties for spin-charge conversion.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88849876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We theoretically study the efficiency limits and performance characteristics of few-layer graphene-semiconductor solar cells (FGSCs) based on a Schottky contact device structure. We model and compare the energy conversion efficiency of various configurations by explicitly considering the non-Richardson thermionic emission across few-layer graphene/semiconductor Schottky heterostructures. The calculations reveal that ABA-stacked trilayer graphene-silicon solar cell exhibits a maximal conversion efficiency exceeding 28% due to a lower reversed saturation current when compared to that of the ABC-stacking configuration. The thermal coefficients of PCE for ABA and ABC stacking FGSCs are -0.064%/K and -0.049%/K, respectively. Our work offers insights for optimal designs of graphene-based solar cells, thus paving a route towards the design of high-performance FGSC for future nanoscale energy converters.
{"title":"Designing few-layer graphene Schottky contact solar cells: Theoretical efficiency limits and parametric optimization","authors":"Xin Zhang, Jicheng Wang, Y. Ang, Juncheng Guo","doi":"10.1063/5.0039431","DOIUrl":"https://doi.org/10.1063/5.0039431","url":null,"abstract":"We theoretically study the efficiency limits and performance characteristics of few-layer graphene-semiconductor solar cells (FGSCs) based on a Schottky contact device structure. We model and compare the energy conversion efficiency of various configurations by explicitly considering the non-Richardson thermionic emission across few-layer graphene/semiconductor Schottky heterostructures. The calculations reveal that ABA-stacked trilayer graphene-silicon solar cell exhibits a maximal conversion efficiency exceeding 28% due to a lower reversed saturation current when compared to that of the ABC-stacking configuration. The thermal coefficients of PCE for ABA and ABC stacking FGSCs are -0.064%/K and -0.049%/K, respectively. Our work offers insights for optimal designs of graphene-based solar cells, thus paving a route towards the design of high-performance FGSC for future nanoscale energy converters.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87359460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-04DOI: 10.1103/PHYSREVAPPLIED.15.034048
Chia-Sheng Hsu, Sou-Chi Chang, Dmitri E. Nikonov, I. Young, A. Naeemi
The negative capacitance (NC) stabilization of a ferroelectric (FE) material can potentially provide an alternative way to further reduce the power consumption in ultra-scaled devices and thus has been of great interest in technology and science in the past decade. In this article, we present a physical picture for a better understanding of the hysteresis-free charge boost effect observed experimentally in metal-ferroelectric-insulator-metal (MFIM) capacitors. By introducing the dielectric (DE) leakage and interfacial trapped charges, our simulations of the hysteresis loops are in a strong agreement with the experimental measurements, suggesting the existence of an interfacial oxide layer at the FE-metal interface in metal-ferroelectric-metal (MFM) capacitors. Based on the pulse switching measurements, we find that the charge enhancement and hysteresis are dominated by the FE domain viscosity and DE leakage, respectively. Our simulation results show that the underlying mechanisms for the observed hysteresis-free charge enhancement in MFIM may be physically different from the alleged NC stabilization and capacitance matching. Moreover, the link between Merz's law and the phenomenological kinetic coefficient is discussed, and the possible cause of the residual charges observed after pulse switching is explained by the trapped charge dynamics at the FE-DE interface. The physical interpretation presented in this work can provide important insights into the NC effect in MFIM capacitors and future studies of low-power logic devices.
{"title":"Hysteresis-Free Negative Capacitance Effect in Metal-Ferroelectric-Insulator-Metal Capacitors with Dielectric Leakage and Interfacial Trapped Charges","authors":"Chia-Sheng Hsu, Sou-Chi Chang, Dmitri E. Nikonov, I. Young, A. Naeemi","doi":"10.1103/PHYSREVAPPLIED.15.034048","DOIUrl":"https://doi.org/10.1103/PHYSREVAPPLIED.15.034048","url":null,"abstract":"The negative capacitance (NC) stabilization of a ferroelectric (FE) material can potentially provide an alternative way to further reduce the power consumption in ultra-scaled devices and thus has been of great interest in technology and science in the past decade. In this article, we present a physical picture for a better understanding of the hysteresis-free charge boost effect observed experimentally in metal-ferroelectric-insulator-metal (MFIM) capacitors. By introducing the dielectric (DE) leakage and interfacial trapped charges, our simulations of the hysteresis loops are in a strong agreement with the experimental measurements, suggesting the existence of an interfacial oxide layer at the FE-metal interface in metal-ferroelectric-metal (MFM) capacitors. Based on the pulse switching measurements, we find that the charge enhancement and hysteresis are dominated by the FE domain viscosity and DE leakage, respectively. Our simulation results show that the underlying mechanisms for the observed hysteresis-free charge enhancement in MFIM may be physically different from the alleged NC stabilization and capacitance matching. Moreover, the link between Merz's law and the phenomenological kinetic coefficient is discussed, and the possible cause of the residual charges observed after pulse switching is explained by the trapped charge dynamics at the FE-DE interface. The physical interpretation presented in this work can provide important insights into the NC effect in MFIM capacitors and future studies of low-power logic devices.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83640266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}