Metamaterials are an emerging type of man-made material capable of obtaining some extraordinary properties that cannot be realized by naturally occurring materials.Due to tremendous application foregrounds in wave man...Metamaterials are an emerging type of man-made material capable of obtaining some extraordinary properties that cannot be realized by naturally occurring materials.Due to tremendous application foregrounds in wave manipulations,metamaterials have gained more and more attraction.Especially,developing research interest of low-frequency vibration attenuation using metamaterials has emerged in the past decades.To better understand the fundamental principle of opening low-frequency(below 100 Hz)band gaps,a general view on the existing literature related to low-frequency band gaps is presented.In this review,some methods for fulfilling low-frequency band gaps are firstly categorized and detailed,and then several strategies for tuning the low-frequency band gaps are summarized.Finally,the potential applications of this type of metamaterial are briefly listed.This review is expected to provide some inspirations for realizing and tuning the low-frequency band gaps by means of summarizing the related literature.展开更多
Recent years,huge progress of first-principles methods has been witnessed in calculating the quasiparticle band gaps,with many-body perturbation theory in the GW approximation being the standard choice,where G refers ...Recent years,huge progress of first-principles methods has been witnessed in calculating the quasiparticle band gaps,with many-body perturbation theory in the GW approximation being the standard choice,where G refers to Green’s function and W denotes the dynamically screened Coulomb interaction.Numerically,the completeness of the basis set has been extensively discussed,but in practice far from carefully addressed.Beyond the static description of the nuclei,the electron–phonon interactions(EPIs)are ubiquitous,which cause zero-point renormalization(ZPR)of the band gaps.Therefore,to obtain high quality band gaps,one needs both accurate quasiparticle energies and accurate treatments of EPIs.In this article,we review methods on this.The completeness of the basis set is analyzed in the framework of linearized augmented plane waves,by adding high-energy local orbitals(HLOs).The electron–phonon matrix elements and self-energy are discussed,followed by the temperature dependence of the band gaps in both perturbative and non-perturbative methods.Applications of such an analysis on bulk wurtzite BeO and monolayer honeycomb BeO are given.Adding HLOs widens their GW_(0) band gaps by∼0.4 eV while ZPR narrows them by similar amount.These influences cancel each other,which explains the fortuitous agreement between experiment and theory when the basis set is incomplete and the EPIs are absent.The phonon-induced renormalization,a term often neglected in calculations of the band gaps,is also emphasized by its large magnitude.展开更多
基金the National Natural Science Foundation of China(Nos.12002122,11972152,and 12122206)the Natural Science Foundation of Hunan Province of China(No.2021JJ40092)the Natural Science Foundation of Chongqing of China(No.cstc2021jcyj-msxmX0461)。
文摘Metamaterials are an emerging type of man-made material capable of obtaining some extraordinary properties that cannot be realized by naturally occurring materials.Due to tremendous application foregrounds in wave manipulations,metamaterials have gained more and more attraction.Especially,developing research interest of low-frequency vibration attenuation using metamaterials has emerged in the past decades.To better understand the fundamental principle of opening low-frequency(below 100 Hz)band gaps,a general view on the existing literature related to low-frequency band gaps is presented.In this review,some methods for fulfilling low-frequency band gaps are firstly categorized and detailed,and then several strategies for tuning the low-frequency band gaps are summarized.Finally,the potential applications of this type of metamaterial are briefly listed.This review is expected to provide some inspirations for realizing and tuning the low-frequency band gaps by means of summarizing the related literature.
基金Project supported by the National Key Research and Development Program of China (Grand Nos. 2016YFA0300900 and 2017YFA0205003)the National Natual Science Foundation of China (Grant Nos. 11934003, 11774003, and 11634001)+3 种基金the Beijing Natural Science FoundationChina (Grant No. Z200004)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB33010400)supported by the High-performance Computing Platform of Peking University,China
文摘Recent years,huge progress of first-principles methods has been witnessed in calculating the quasiparticle band gaps,with many-body perturbation theory in the GW approximation being the standard choice,where G refers to Green’s function and W denotes the dynamically screened Coulomb interaction.Numerically,the completeness of the basis set has been extensively discussed,but in practice far from carefully addressed.Beyond the static description of the nuclei,the electron–phonon interactions(EPIs)are ubiquitous,which cause zero-point renormalization(ZPR)of the band gaps.Therefore,to obtain high quality band gaps,one needs both accurate quasiparticle energies and accurate treatments of EPIs.In this article,we review methods on this.The completeness of the basis set is analyzed in the framework of linearized augmented plane waves,by adding high-energy local orbitals(HLOs).The electron–phonon matrix elements and self-energy are discussed,followed by the temperature dependence of the band gaps in both perturbative and non-perturbative methods.Applications of such an analysis on bulk wurtzite BeO and monolayer honeycomb BeO are given.Adding HLOs widens their GW_(0) band gaps by∼0.4 eV while ZPR narrows them by similar amount.These influences cancel each other,which explains the fortuitous agreement between experiment and theory when the basis set is incomplete and the EPIs are absent.The phonon-induced renormalization,a term often neglected in calculations of the band gaps,is also emphasized by its large magnitude.
