Time-reversal symmetry(TRS)breaking induced dissipationless topological phonon edge modes provide an unprecedented way to manipulate phonon transport.However,the effect of TRS breaking on the transport properties of b...Time-reversal symmetry(TRS)breaking induced dissipationless topological phonon edge modes provide an unprecedented way to manipulate phonon transport.However,the effect of TRS breaking on the transport properties of bulk phonon modes is still unclear.In this work,we assess the effect of local TRS-breaking domains on the transport properties of bulk phonon modes in a two-dimensional(2D)hexagonal phononic lattice model.The results show that bulk phonon modes can be strongly scattered by local TRS breaking owing to the shift of the local phonon band gap,which results in significant suppression of phonon transmission.Moreover,we show that the aperiodic distribution of local TRS-breaking domains can induce phonon Anderson localization,and the localization length can be effectively tuned by the strength of TRS breaking.Our study suggests that TRS breaking can not only be used to construct dissipationless topological phonon edge states,but also be used to block the transmission of bulk phonon modes by carefully controlling the size and distribution of TRS-breaking domains.Such results provide a highly alternative way for manipulating energy flux at the nanoscale.展开更多
Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric materials.Here,by using first-principles calculations and semiclassical Boltzmann transpo...Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric materials.Here,by using first-principles calculations and semiclassical Boltzmann transport theory,we systemically investigate the carrier transport and thermoelectric properties of monolayer Janus GaInX_(3)(X=S,Se,Te).It is found that the lattice thermal conductivities can reach values as low as 3.07 W·m^(-1)·K^(-1),1.16 W·m^(-1)·K^(-1)and 0.57 W·m^(-1)·K^(-1)for GaInS_(3),GaInSe_(3),and GaInTe_(3),respectively,at room temperature.This notably low thermal conductivity is attributed to strong acoustic-optical phonon coupling caused by the presence of low-frequency optical phonons in GaInX_(3) materials.Furthermore,by integrating the charac teristics of electronic and thermal transport,the dimensionless figure of merit ZT can reach maximum values of 0.95,2.37,and 3.00 for GaInS_(3),GaInSe_(3),and GaInTe_(3),respectively.Our results suggest that monolayer Janus GaInX_(3)(X=S,Se,Te)is a promising candidate for thermoelectric and heat management applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12404011)the Natural Science Foundation of Hunan Province(Grant No.2023JJ40273)the Scientific Research Foundation of Hunan Provincial Education Department(Grant No.23B0495).
文摘Time-reversal symmetry(TRS)breaking induced dissipationless topological phonon edge modes provide an unprecedented way to manipulate phonon transport.However,the effect of TRS breaking on the transport properties of bulk phonon modes is still unclear.In this work,we assess the effect of local TRS-breaking domains on the transport properties of bulk phonon modes in a two-dimensional(2D)hexagonal phononic lattice model.The results show that bulk phonon modes can be strongly scattered by local TRS breaking owing to the shift of the local phonon band gap,which results in significant suppression of phonon transmission.Moreover,we show that the aperiodic distribution of local TRS-breaking domains can induce phonon Anderson localization,and the localization length can be effectively tuned by the strength of TRS breaking.Our study suggests that TRS breaking can not only be used to construct dissipationless topological phonon edge states,but also be used to block the transmission of bulk phonon modes by carefully controlling the size and distribution of TRS-breaking domains.Such results provide a highly alternative way for manipulating energy flux at the nanoscale.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12104145,62201208,and 12374040)。
文摘Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric materials.Here,by using first-principles calculations and semiclassical Boltzmann transport theory,we systemically investigate the carrier transport and thermoelectric properties of monolayer Janus GaInX_(3)(X=S,Se,Te).It is found that the lattice thermal conductivities can reach values as low as 3.07 W·m^(-1)·K^(-1),1.16 W·m^(-1)·K^(-1)and 0.57 W·m^(-1)·K^(-1)for GaInS_(3),GaInSe_(3),and GaInTe_(3),respectively,at room temperature.This notably low thermal conductivity is attributed to strong acoustic-optical phonon coupling caused by the presence of low-frequency optical phonons in GaInX_(3) materials.Furthermore,by integrating the charac teristics of electronic and thermal transport,the dimensionless figure of merit ZT can reach maximum values of 0.95,2.37,and 3.00 for GaInS_(3),GaInSe_(3),and GaInTe_(3),respectively.Our results suggest that monolayer Janus GaInX_(3)(X=S,Se,Te)is a promising candidate for thermoelectric and heat management applications.
