Thermal diodes,based on the thermal rectification effect,have demonstrated great promise for advanced thermal management.In previous studies,almost all thermal diodes were discussed under the condition of steady state...Thermal diodes,based on the thermal rectification effect,have demonstrated great promise for advanced thermal management.In previous studies,almost all thermal diodes were discussed under the condition of steady states,while the heat source of a practical thermal system often operates under dynamically fluctuating temperatures.Therefore,in this work,we employ finite element simulation to investigate transient thermal rectification behaviors in a well-built heterojunction which exhibits intrinsic thermal rectification effect under steady state.Unidirectional energy transport in the heterojunction system,decoupled from the steady-state temperature bias,is observed under a time-dependent fluctuating heat source.This phenomenon enables straightforward realization of both giant thermal rectification and negative thermal transport.Furthermore,a series of novel thermal regulation strategies are unveiled by adjusting the average temperature,frequency,and phase of the heat source.Our work not only deepens fundamental understanding of thermal regulation in time-dependent oscillating temperature systems but also uncovers many unexplored energy-saving thermal management strategies.展开更多
Pursuing significant thermal rectification effect with minimal temperature differences is critical for thermal rectifiers.While asymmetric structures enable spectral matching,they inherently limit thermal rectificatio...Pursuing significant thermal rectification effect with minimal temperature differences is critical for thermal rectifiers.While asymmetric structures enable spectral matching,they inherently limit thermal rectification performance.To address this issue,we developed a thermal rectification structure comprising a current-biased graphene-coated silicon carbide(SiC)substrate paired with another graphene-coated SiC substrate separated by a nanoscale vacuum gap.A current-biased graphene sheet generates nonreciprocal effect that actively modulates radiative energy transfer.Our theoretical framework demonstrates that the current-biased graphene achieves a high thermal diode efficiency even under a modest temperature difference.Remarkably,the thermal diode efficiency exceeds 0.8 at a temperature difference of just 100 K(between 300 K and 400 K).These findings highlight the synergistic enhancement from graphene coatings and current biasing,providing a viable strategy for nanoscale thermal management applications.展开更多
Carbon nanotubes(CNTs)are widely used in various fields owing to their unique properties.In this study,three different types of nitrogen-doped CNT heterojunctions were constructed:parallel-doped(PCNT),vertically doped...Carbon nanotubes(CNTs)are widely used in various fields owing to their unique properties.In this study,three different types of nitrogen-doped CNT heterojunctions were constructed:parallel-doped(PCNT),vertically doped(VCNT),and mesh-doped(MCNT).Non-equilibrium molecular dynamics(NEMD)simulations were conducted to investigate their heat flux and thermal rectification(TR)effects.The results show that heat flux preferentially flows from nitrogen-doped regions to undoped regions,exhibiting distinct thermal rectification behavior,with PCNT showing the most pronounced effect.Interestingly,the TR ratio of the zigzag PCNT is significantly higher than that of the armchair PCNT.Subsequently,we examined the effects of system length and diameter on the TR ratio of the PCNT and found that the TR ratio increases and then decreases with increasing model length.In addition,the effect of defect density on the heat flux of the PCNT is peculiar.The phonon density of states,phonon dispersion,participation ratio,and phonon spectral heat flux were analyzed to elucidate the thermal transport behavior of phonons in the nanotubes.This study provides insights into the development and design of nitrogen-doped CNT thermal rectifiers.展开更多
Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device...Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level,which results in a gap to real applications.Here,we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite thermal rectification material(TRM)based on PCM and reduced graphene oxide(rGO)aerogel to ordinary concrete walls(CWs).The design is evaluated in detail by combining experiments and finite element analysis.It is found that,TRM can regulate the temperature difference on both sides of the TRM/CWs system by thermal rectification.The difference in two directions reaches to 13.8 K at the heat flow of 80 W/m^(2).In addition,the larger the change of thermal conductivity before and after phase change of TRM is,the more effective it is for regulating temperature difference in two directions.The stated technology has a wide range of applications for the thermal energy control in buildings with specific temperature requirements.展开更多
Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in...Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in electronic device applications.However,achieving high thermal rectification efficiency or rectification ratio is still a scientific challenge.In this work,we performed a systematic simulation of thermal rectification by considering both efforts of thermal conductivity asymmetry and geometrical asymmetry in a multi-segment thermal rectifier.It is found that the high asymmetry of thermal conductivity and the asymmetry of the geometric structure of multi-segment thermal rectifiers can significantly enhance the thermal rectification,and the combination of both thermal conductivity asymmetry and geometrical asymmetry can further improve thermal rectification efficiency.This work suggests a possible way for improving thermal rectification devices by asymmetry engineering.展开更多
Thermal rectification,or the asymmetric transport of heat along a structure,has recently been investigated as a poten-tial solution to the thermal management issues that accompany the miniaturization of electronic dev...Thermal rectification,or the asymmetric transport of heat along a structure,has recently been investigated as a poten-tial solution to the thermal management issues that accompany the miniaturization of electronic devices.Applications of this concept in thermal logic circuits analogous to existing electronics-based processor logic have also been proposed.This review highlights some of the techniques that have been recently investigated for their potential to induce asymmetric thermal con-ductivity in solid-state structures that are composed of materials of interest to the electronics industry.These rectification ap-proaches are compared in terms of their quantitative performance,as well as the range of practical applications that they would be best suited to.Techniques applicable to a range of length scales,from the continuum regime to quantum dots,are dis-cussed,and where available,experimental findings that build upon numerical simulations or analytical predictions are also high-lighted.展开更多
Using nonequilibrium molecular dynamics simulations, a comprehensive study of the asymmetric heat conduction in the composite system consisting of the Frenkel-Kontorova （FK） model and Fermi-Pasta-Ulam （FPU） model ...Using nonequilibrium molecular dynamics simulations, a comprehensive study of the asymmetric heat conduction in the composite system consisting of the Frenkel-Kontorova （FK） model and Fermi-Pasta-Ulam （FPU） model is conducted. The calculated results show that in a larger system, the rectifying direction can be reversed only by adjusting the thermal bias. Moreover, the rectification reversal depends critically on the system size and the properties of the interface. The mechanisms of the two types of asymmetric heat conduction induced by nonlinearity are discussed. Considering the novel asymmetric heat conduction in the system, it may possess possible applications to manage the thermal rectification in situ directionally without re-building the structure.展开更多
Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction.In this study,we propose to implement the thermal rectificatio...Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction.In this study,we propose to implement the thermal rectification phenomenon in an asymmetric solid–liquid–solid sandwiched system with a nano-structured interface.By using the non-equilibrium molecular dynamics simulations,the thermal transport through the solid–liquid–solid system is examined,and the thermal rectification phenomenon can be observed.It is revealed that the thermal rectification effect can be attributed to the significant difference in the interfacial thermal resistance between Cassie and Wenzel states when reversing the temperature bias.In addition,effects of the liquid density,solid–liquid bonding strength and nanostructure size on the thermal rectification are examined.The findings may provide a new way for designs of certain thermal devices.展开更多
Thermal rectification refers to the asymmetry in heat transfer capability when subjected to forward and reverse temperature gradients.A thermal cloak can render objects invisible in thermal fields by redirecting heat ...Thermal rectification refers to the asymmetry in heat transfer capability when subjected to forward and reverse temperature gradients.A thermal cloak can render objects invisible in thermal fields by redirecting heat flux pathways.In this paper,we present a thermal diode model based on a bi-layer thermal cloak system that incorporates a composite heat-fluxattracting layer with asymmetric,temperature-dependent thermal conductivity.In the forward case,the heat flux bypasses the cloaking region while maintaining undistorted background isotherm contours,whereas in the reverse case,the thermal cloak fails to function and the device effectively insulates heat.Consequently,thermal rectification occurs in the bi-layer thermal cloak system.A significant increase in the thermal rectification ratio is observed as the temperature gradient increases.By optimizing the system dimensions,a peak rectification ratio of 11.06 is achieved.This study provides physical insight and a design framework for developing novel thermal diodes with dual-functional thermal management capabilities.展开更多
In this study,by using the nonequilibrium molecular dynamics and the kinetic theory,we examine the tailored nanoscale thermal transport via a gas-filled nanogap structure with mechanically-controllable nanopillars in ...In this study,by using the nonequilibrium molecular dynamics and the kinetic theory,we examine the tailored nanoscale thermal transport via a gas-filled nanogap structure with mechanically-controllable nanopillars in one surface only,i.e.,changing nanopillar height.It is found that both the thermal rectification and negative differential thermal resistance(NDTR)effects can be substantially enhanced by controlling the nanopillar height.The maximum thermal rectification ratio can reach 340%and the△T range with NDTR can be significantly enlarged,which can be attributed to the tailored asymmetric thermal resistance via controlled adsorption in height-changing nanopillars,especially at a large temperature difference.These tunable thermal rectification and NDTR mechanisms provide insights for the design of thermal management systems.展开更多
Thermal rectification(TR)is a phenomenon akin to electrical rectification.It has a high thermal conductivity(k)in one direction,enabling efficient heat dissipation,as well as a low k in the opposite direction,impeding...Thermal rectification(TR)is a phenomenon akin to electrical rectification.It has a high thermal conductivity(k)in one direction,enabling efficient heat dissipation,as well as a low k in the opposite direction,impeding heat influx.With the rapid development of nanotechnology in recent years,the active control and regulation of heat conduction on the nanoscale has become a critical mission.Graphene,a prominent two-dimensional(2D)material,is highly regarded for its exceptional thermal transport characteristics.There have been studies and achievements both theoretically and experimentally since its discovery.In this review,we establish a bridge between fundamental research and application studies for graphene-based thermal rectifier as follows.Firstly,we summarize the established 2D heat conduction theories and low-dimensional simulation methods.Secondly,we review the progress of experimental techniques and device structures based on 2D theories for graphene-based thermal rectifier.Then,we discuss several applications of thermal rectifier,including thermal logic circuits and thermoelectric power generation system.Finally,we present the potential applications of graphene-based thermal rectifiers previously unexplored,such as microelectronic thermal management and thermal decoupling for flexible equipment.We hope that advancements in morphology and fabrication techniques will lead to widespread use of graphene-based thermal rectifiers in various thermal systems to solve diverse thermal management problems in the near future.展开更多
Thermal rectification is a promising way to manipulate the heat flow,in which thermal phonons are spectrally and collectively controlled.As phononic devices are mostly relying on monochromatic phonons,in this work we ...Thermal rectification is a promising way to manipulate the heat flow,in which thermal phonons are spectrally and collectively controlled.As phononic devices are mostly relying on monochromatic phonons,in this work we propose a phononic rectifier based on the carbon schwarzite host–vip system.By using molecular dynamic simulations,we demonstrate that the phononic rectification only happens at a specific frequency of the hybridized mode for the host–vip system,due to its strong confinement effect.Moreover,a significant rectification efficiency,~134%,is observed,which is larger than most of the previously observed efficiencies.The study of length and temperature effects on the phononic rectification shows that the monochromaticity and frequency of the rectified thermal phonons depend on the intrinsic anharmonicity of the host–vip system and that the on-center rattling configuration with weak anharmonicity is preferable.Our study provides a new perspective on the rectification of thermal phonons,which would be important for controlling monochromatic thermal phonons in phononic devices.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2023YFA1407001)Department of Science and Technology of Jiangsu Province(Grant No.BK20220032)。
文摘Thermal diodes,based on the thermal rectification effect,have demonstrated great promise for advanced thermal management.In previous studies,almost all thermal diodes were discussed under the condition of steady states,while the heat source of a practical thermal system often operates under dynamically fluctuating temperatures.Therefore,in this work,we employ finite element simulation to investigate transient thermal rectification behaviors in a well-built heterojunction which exhibits intrinsic thermal rectification effect under steady state.Unidirectional energy transport in the heterojunction system,decoupled from the steady-state temperature bias,is observed under a time-dependent fluctuating heat source.This phenomenon enables straightforward realization of both giant thermal rectification and negative thermal transport.Furthermore,a series of novel thermal regulation strategies are unveiled by adjusting the average temperature,frequency,and phase of the heat source.Our work not only deepens fundamental understanding of thermal regulation in time-dependent oscillating temperature systems but also uncovers many unexplored energy-saving thermal management strategies.
基金Project supported by the National Natural Science Foundation of China(Grant No.12364008)the Ph.D.Research Startup Foundation of Yan’an University(Grant No.YDBK2019-54)the Yan’an High-level Talent Special Project(Grant No.2019263166)。
文摘Pursuing significant thermal rectification effect with minimal temperature differences is critical for thermal rectifiers.While asymmetric structures enable spectral matching,they inherently limit thermal rectification performance.To address this issue,we developed a thermal rectification structure comprising a current-biased graphene-coated silicon carbide(SiC)substrate paired with another graphene-coated SiC substrate separated by a nanoscale vacuum gap.A current-biased graphene sheet generates nonreciprocal effect that actively modulates radiative energy transfer.Our theoretical framework demonstrates that the current-biased graphene achieves a high thermal diode efficiency even under a modest temperature difference.Remarkably,the thermal diode efficiency exceeds 0.8 at a temperature difference of just 100 K(between 300 K and 400 K).These findings highlight the synergistic enhancement from graphene coatings and current biasing,providing a viable strategy for nanoscale thermal management applications.
基金supported by the National Natural Science Foundation of China(Grant No.52476071)the Natural Science Foundation of Hebei Province(Grant No.A2024502008).
文摘Carbon nanotubes(CNTs)are widely used in various fields owing to their unique properties.In this study,three different types of nitrogen-doped CNT heterojunctions were constructed:parallel-doped(PCNT),vertically doped(VCNT),and mesh-doped(MCNT).Non-equilibrium molecular dynamics(NEMD)simulations were conducted to investigate their heat flux and thermal rectification(TR)effects.The results show that heat flux preferentially flows from nitrogen-doped regions to undoped regions,exhibiting distinct thermal rectification behavior,with PCNT showing the most pronounced effect.Interestingly,the TR ratio of the zigzag PCNT is significantly higher than that of the armchair PCNT.Subsequently,we examined the effects of system length and diameter on the TR ratio of the PCNT and found that the TR ratio increases and then decreases with increasing model length.In addition,the effect of defect density on the heat flux of the PCNT is peculiar.The phonon density of states,phonon dispersion,participation ratio,and phonon spectral heat flux were analyzed to elucidate the thermal transport behavior of phonons in the nanotubes.This study provides insights into the development and design of nitrogen-doped CNT thermal rectifiers.
基金This work was supported in part by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies(JIAOT KF202204)in part by STI 2030—Major Projects under Grant 2022ZD0209200+2 种基金in part by National Natural Science Foundation of China under Grant 62374099,Grant 62022047in part by Beijing Natural Science-Xiaomi Innovation Joint Fund under Grant L233009in part by the Tsinghua-Toyota JointResearch Fund,in part by the Daikin-Tsinghua Union Program,in part sponsored by CIE-Tencent Robotics XRhino-Bird Focused Research Program.
文摘Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level,which results in a gap to real applications.Here,we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite thermal rectification material(TRM)based on PCM and reduced graphene oxide(rGO)aerogel to ordinary concrete walls(CWs).The design is evaluated in detail by combining experiments and finite element analysis.It is found that,TRM can regulate the temperature difference on both sides of the TRM/CWs system by thermal rectification.The difference in two directions reaches to 13.8 K at the heat flow of 80 W/m^(2).In addition,the larger the change of thermal conductivity before and after phase change of TRM is,the more effective it is for regulating temperature difference in two directions.The stated technology has a wide range of applications for the thermal energy control in buildings with specific temperature requirements.
基金Project supported by the National Natural Science Foundation of China(Grant No.12274355)Xiamen University Malaysia Research Fund(Grant Nos.XMUMRF/2022C9/IORI/003 and XMUMRF/2022-C10/IORI/004)。
文摘Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in electronic device applications.However,achieving high thermal rectification efficiency or rectification ratio is still a scientific challenge.In this work,we performed a systematic simulation of thermal rectification by considering both efforts of thermal conductivity asymmetry and geometrical asymmetry in a multi-segment thermal rectifier.It is found that the high asymmetry of thermal conductivity and the asymmetry of the geometric structure of multi-segment thermal rectifiers can significantly enhance the thermal rectification,and the combination of both thermal conductivity asymmetry and geometrical asymmetry can further improve thermal rectification efficiency.This work suggests a possible way for improving thermal rectification devices by asymmetry engineering.
基金fully funded by the Commonwealth Scholarship Commission in the UK and Imperial College London
文摘Thermal rectification,or the asymmetric transport of heat along a structure,has recently been investigated as a poten-tial solution to the thermal management issues that accompany the miniaturization of electronic devices.Applications of this concept in thermal logic circuits analogous to existing electronics-based processor logic have also been proposed.This review highlights some of the techniques that have been recently investigated for their potential to induce asymmetric thermal con-ductivity in solid-state structures that are composed of materials of interest to the electronics industry.These rectification ap-proaches are compared in terms of their quantitative performance,as well as the range of practical applications that they would be best suited to.Techniques applicable to a range of length scales,from the continuum regime to quantum dots,are dis-cussed,and where available,experimental findings that build upon numerical simulations or analytical predictions are also high-lighted.
基金supported by the Natural Science Foundation of Hunan Province,China(Grant No.12JJ3009)the Changsha Science and Technology Plan Projects,Chinathe Science and Technology Plan Projects of Hunan Province,China(Grant No.2013SK3148)
文摘Using nonequilibrium molecular dynamics simulations, a comprehensive study of the asymmetric heat conduction in the composite system consisting of the Frenkel-Kontorova （FK） model and Fermi-Pasta-Ulam （FPU） model is conducted. The calculated results show that in a larger system, the rectifying direction can be reversed only by adjusting the thermal bias. Moreover, the rectification reversal depends critically on the system size and the properties of the interface. The mechanisms of the two types of asymmetric heat conduction induced by nonlinearity are discussed. Considering the novel asymmetric heat conduction in the system, it may possess possible applications to manage the thermal rectification in situ directionally without re-building the structure.
基金the National Natural Science Foundation of China(Grant No.51976002)the Beijing Nova Program of Science and Technology(Grant No.Z191100001119033)。
文摘Thermal rectification refers to the phenomenon by which the magnitude of the heat flux in one direction is much larger than that in the opposite direction.In this study,we propose to implement the thermal rectification phenomenon in an asymmetric solid–liquid–solid sandwiched system with a nano-structured interface.By using the non-equilibrium molecular dynamics simulations,the thermal transport through the solid–liquid–solid system is examined,and the thermal rectification phenomenon can be observed.It is revealed that the thermal rectification effect can be attributed to the significant difference in the interfacial thermal resistance between Cassie and Wenzel states when reversing the temperature bias.In addition,effects of the liquid density,solid–liquid bonding strength and nanostructure size on the thermal rectification are examined.The findings may provide a new way for designs of certain thermal devices.
文摘Thermal rectification refers to the asymmetry in heat transfer capability when subjected to forward and reverse temperature gradients.A thermal cloak can render objects invisible in thermal fields by redirecting heat flux pathways.In this paper,we present a thermal diode model based on a bi-layer thermal cloak system that incorporates a composite heat-fluxattracting layer with asymmetric,temperature-dependent thermal conductivity.In the forward case,the heat flux bypasses the cloaking region while maintaining undistorted background isotherm contours,whereas in the reverse case,the thermal cloak fails to function and the device effectively insulates heat.Consequently,thermal rectification occurs in the bi-layer thermal cloak system.A significant increase in the thermal rectification ratio is observed as the temperature gradient increases.By optimizing the system dimensions,a peak rectification ratio of 11.06 is achieved.This study provides physical insight and a design framework for developing novel thermal diodes with dual-functional thermal management capabilities.
基金the National Natural Science Foundation of China(grants Nos.51976002 and 51776007)Beijing Nova Program of Science and Technology(No.Z191100001119033)the Young Talent Project of Beijing Municipal Education Committee(No.CIT&TCD201904015)。
文摘In this study,by using the nonequilibrium molecular dynamics and the kinetic theory,we examine the tailored nanoscale thermal transport via a gas-filled nanogap structure with mechanically-controllable nanopillars in one surface only,i.e.,changing nanopillar height.It is found that both the thermal rectification and negative differential thermal resistance(NDTR)effects can be substantially enhanced by controlling the nanopillar height.The maximum thermal rectification ratio can reach 340%and the△T range with NDTR can be significantly enlarged,which can be attributed to the tailored asymmetric thermal resistance via controlled adsorption in height-changing nanopillars,especially at a large temperature difference.These tunable thermal rectification and NDTR mechanisms provide insights for the design of thermal management systems.
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200in part by National Natural Science Foundation of China under Grant Nos.62374099+3 种基金in part by the Tsinghua-Toyota Joint Research Fund,in part by Beijing Natural Science Foundation-Xiaomi Innovation Joint Fund(L233009in part by the Daikin Tsinghua Union Program,in part supported by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies(JIAOT KF202204)in part by Independent Research Program of School of Integrated Circuits,Tsinghua UniversityThis work was also sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Program.
文摘Thermal rectification(TR)is a phenomenon akin to electrical rectification.It has a high thermal conductivity(k)in one direction,enabling efficient heat dissipation,as well as a low k in the opposite direction,impeding heat influx.With the rapid development of nanotechnology in recent years,the active control and regulation of heat conduction on the nanoscale has become a critical mission.Graphene,a prominent two-dimensional(2D)material,is highly regarded for its exceptional thermal transport characteristics.There have been studies and achievements both theoretically and experimentally since its discovery.In this review,we establish a bridge between fundamental research and application studies for graphene-based thermal rectifier as follows.Firstly,we summarize the established 2D heat conduction theories and low-dimensional simulation methods.Secondly,we review the progress of experimental techniques and device structures based on 2D theories for graphene-based thermal rectifier.Then,we discuss several applications of thermal rectifier,including thermal logic circuits and thermoelectric power generation system.Finally,we present the potential applications of graphene-based thermal rectifiers previously unexplored,such as microelectronic thermal management and thermal decoupling for flexible equipment.We hope that advancements in morphology and fabrication techniques will lead to widespread use of graphene-based thermal rectifiers in various thermal systems to solve diverse thermal management problems in the near future.
基金Project supported in part by the National Natural Science Foundation of China(Grant No.11890703)Science and Technology Commission of Shanghai Municipality+4 种基金China(Grant Nos.19ZR1478600 and 18JC1410900)the Fundamental Research Funds for the Central UniversitiesChina(Grant No.22120200069)partially supported by CREST JST(Grant Nos.JPMJCR19Q3 and JPMJCR19I1)financial support from China Scholarship Council。
文摘Thermal rectification is a promising way to manipulate the heat flow,in which thermal phonons are spectrally and collectively controlled.As phononic devices are mostly relying on monochromatic phonons,in this work we propose a phononic rectifier based on the carbon schwarzite host–vip system.By using molecular dynamic simulations,we demonstrate that the phononic rectification only happens at a specific frequency of the hybridized mode for the host–vip system,due to its strong confinement effect.Moreover,a significant rectification efficiency,~134%,is observed,which is larger than most of the previously observed efficiencies.The study of length and temperature effects on the phononic rectification shows that the monochromaticity and frequency of the rectified thermal phonons depend on the intrinsic anharmonicity of the host–vip system and that the on-center rattling configuration with weak anharmonicity is preferable.Our study provides a new perspective on the rectification of thermal phonons,which would be important for controlling monochromatic thermal phonons in phononic devices.
