Electro-optic effects allow control of the ow of light using electric fields,and are of utmost importance for today’s information and communication technologies,such as TV displays and fiber optics.The search for lar...Electro-optic effects allow control of the ow of light using electric fields,and are of utmost importance for today’s information and communication technologies,such as TV displays and fiber optics.The search for large electro-optic constants in films is essential to the miniaturization and increased efficiency of electro-optic devices.In this work,we demonstrate that strain-engineering in PbTiO_(3) films allows to selectively choose which electro-optic constant to improve.Unclamped electro-optic constants larger than 100 pm V^(−1) are predicted,either by driving the softening of an optical phonon mode at a phase transition boundary under tensile strain,or by generating the equivalent of a negative pressure via compressive strain to obtain large piezoelectric constants.In particular,a r_(13) electro-optic coefficient twice as large as the one of the commonly used LiNbO_(3) electro-optic material is found here when growing PbTiO_(3) on the technologicallyimportant Si substrate.展开更多
After publishing this article,we realized that the calculation of the piezoelectric constants dij by Density Functional Perturbation Theory(DFPT),as explained in the methods described in the original version of the Su...After publishing this article,we realized that the calculation of the piezoelectric constants dij by Density Functional Perturbation Theory(DFPT),as explained in the methods described in the original version of the Supplementary Information,are incorrect in the case of a partially clamped situation.The correct methodology is to inverse the subspace matrix of elastic constants.展开更多
Negative capacitance in BaTiO_(3)/SrTiO_(3) superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model,using fluctuation formulas for responses to the local macroscopic field ...Negative capacitance in BaTiO_(3)/SrTiO_(3) superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model,using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields.We show that epitaxial strain can tune the negative capacitance of the BaTiO_(3) ferroelectric layer and the overall capacitance of the system.In addition,we predict and explain an original switching of the negative capacitance from the BaTiO3 layer to the SrTiO_(3) layer at low temperatures for intermediate strains.展开更多
基金C.P.thanks the AHPCC for use of computing ressources.C.P.and L.B.thank the ARO grant W911NF-16-1-0227.S.P.and L.B.acknowledge DARPA grant HR0011-15-2-0038(MATRIX program).
文摘Electro-optic effects allow control of the ow of light using electric fields,and are of utmost importance for today’s information and communication technologies,such as TV displays and fiber optics.The search for large electro-optic constants in films is essential to the miniaturization and increased efficiency of electro-optic devices.In this work,we demonstrate that strain-engineering in PbTiO_(3) films allows to selectively choose which electro-optic constant to improve.Unclamped electro-optic constants larger than 100 pm V^(−1) are predicted,either by driving the softening of an optical phonon mode at a phase transition boundary under tensile strain,or by generating the equivalent of a negative pressure via compressive strain to obtain large piezoelectric constants.In particular,a r_(13) electro-optic coefficient twice as large as the one of the commonly used LiNbO_(3) electro-optic material is found here when growing PbTiO_(3) on the technologicallyimportant Si substrate.
文摘After publishing this article,we realized that the calculation of the piezoelectric constants dij by Density Functional Perturbation Theory(DFPT),as explained in the methods described in the original version of the Supplementary Information,are incorrect in the case of a partially clamped situation.The correct methodology is to inverse the subspace matrix of elastic constants.
基金R.W.and L.B.acknowledge ARO Grant No.W911NF-16-1-0227C.P.and L.B.thank the DARPA Grant No.HR0011-15-2-0038(MATRIX program)+4 种基金S.P.and L.B.also acknowledge ONR Grant No.N00014-17-1-2818Some computations were made possible by MRI Grant No.0722625 from NSF,ONR Grant No.N00014-15-1-2881(DURIP)a Challenge grant from the Department of DefenseC.P.also acknowledges the support from a public grant overseen by the French National Research Agency(ANR)as part of the“Investissements d’Avenir”program(Labex NanoSaclay,reference:ANR-10-LABX-0035)S.P.appreciates support of the Russian Ministry of Science and Higher Education(State assignment in the field of scientific activity,Southern Federal University,2020).
文摘Negative capacitance in BaTiO_(3)/SrTiO_(3) superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model,using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields.We show that epitaxial strain can tune the negative capacitance of the BaTiO_(3) ferroelectric layer and the overall capacitance of the system.In addition,we predict and explain an original switching of the negative capacitance from the BaTiO3 layer to the SrTiO_(3) layer at low temperatures for intermediate strains.
