We developed a general framework for hybrid quantum-classical computing of molecular and periodic embedding approaches based on an orbital space separation of the fragment and environment degrees of freedom.Wedemonstr...We developed a general framework for hybrid quantum-classical computing of molecular and periodic embedding approaches based on an orbital space separation of the fragment and environment degrees of freedom.Wedemonstrate itspotentialbypresenting a specific implementationof periodic range-separated DFT coupled to a quantum circuit ansatz,whereby the variational quantum eigensolver and the quantum equation-of-motion algorithm are used to obtain the low-lying spectrum of the embedded fragment Hamiltonian.The application of this scheme to study localized electronic states in materials is showcased through the accurate prediction of the optical properties of the neutral oxygen vacancy in magnesium oxide(MgO).Despite some discrepancies in the position of the main absorption band,the method demonstrates competitive performance compared to state-of-the-art ab initio approaches,particularly evidenced by the excellent agreement with the experimental photoluminescence emission peak.展开更多
A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light e...A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light emitting diode(OLED)applications,was performed with the quantum Equation-Of-Motion Variational Quantum Eigensolver(qEOM-VQE)and Variational Quantum Deflation(VQD)algorithms on quantum simulators and devices.These quantum simulations were performed with double zeta quality basis sets on an active space comprising the highest occupied and lowest unoccupied molecular orbitals(HOMO,LUMO)of the TADF molecules.The differences in energy separations between S_(1) and T_(1)(ΔEST)predicted by calculations on quantum simulators were found to be in excellent agreement with experimental data.Differences of 17 and 88 mHa with respect to exact energies were found for excited states by using the qEOM-VQE and VQD algorithms,respectively,to perform simulations on quantum devices without error mitigation.By utilizing state tomography to purify the quantum states and correct energy values,the large errors found for unmitigated results could be improved to differences of,at most,4 mHa with respect to exact values.Consequently,excellent agreement could be found between values ofΔEST predicted by quantum simulations and those found in experiments.展开更多
The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geome...The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geometries on noisy intermediate-scalequantum devices, we proposed a strategy that combined a chemistry-inspired spin-restricted ansatz and a new excited statecalculation method called the variational quantum eigensolver under automatically-adjusted constraints (VQE/AC). Unlike theconventional excited state calculation method, called the variational quantum deflation, the VQE/AC does not require the pre-determination of constraint weights and has the potential to describe smooth potential energy surfaces. To validate this strategy,we performed the excited state calculations at the FC and CI geometries of ethylene and phenol blue at the complete active spaceself-consistent field (CASSCF) level of theory, and found that the energy errors were at most 2 kcal mol−1 even on the ibm_kawasakidevice.展开更多
基金supported by the NCCR MARVEL,a National Center of Competence in Research,funded by the Swiss National Science Foundation(grant number 205602)supported by the Swiss National Science Foundation in the formof Ambizione grant No.PZ00P2_174227(VVR).
文摘We developed a general framework for hybrid quantum-classical computing of molecular and periodic embedding approaches based on an orbital space separation of the fragment and environment degrees of freedom.Wedemonstrate itspotentialbypresenting a specific implementationof periodic range-separated DFT coupled to a quantum circuit ansatz,whereby the variational quantum eigensolver and the quantum equation-of-motion algorithm are used to obtain the low-lying spectrum of the embedded fragment Hamiltonian.The application of this scheme to study localized electronic states in materials is showcased through the accurate prediction of the optical properties of the neutral oxygen vacancy in magnesium oxide(MgO).Despite some discrepancies in the position of the main absorption band,the method demonstrates competitive performance compared to state-of-the-art ab initio approaches,particularly evidenced by the excellent agreement with the experimental photoluminescence emission peak.
基金Q.G.,M.S.,H.C.W.,E.W.,Y.O.,H.N.and N.Y.acknowledge support from MEXT Quantum Leap Flagship Program Grant Number JP-MXS0118067285 and JP-MXS0120319794。
文摘A quantum chemistry study of the first singlet(S_(1))and triplet(T_(1))excited states of phenylsulfonyl-carbazole compounds,proposed as useful thermally activated delayed fluorescence(TADF)emitters for organic light emitting diode(OLED)applications,was performed with the quantum Equation-Of-Motion Variational Quantum Eigensolver(qEOM-VQE)and Variational Quantum Deflation(VQD)algorithms on quantum simulators and devices.These quantum simulations were performed with double zeta quality basis sets on an active space comprising the highest occupied and lowest unoccupied molecular orbitals(HOMO,LUMO)of the TADF molecules.The differences in energy separations between S_(1) and T_(1)(ΔEST)predicted by calculations on quantum simulators were found to be in excellent agreement with experimental data.Differences of 17 and 88 mHa with respect to exact energies were found for excited states by using the qEOM-VQE and VQD algorithms,respectively,to perform simulations on quantum devices without error mitigation.By utilizing state tomography to purify the quantum states and correct energy values,the large errors found for unmitigated results could be improved to differences of,at most,4 mHa with respect to exact values.Consequently,excellent agreement could be found between values ofΔEST predicted by quantum simulations and those found in experiments.
基金This work was supported by JSPS KAKENHI Grant no.JP17H06445,20K05438,and JST Gannt no.JPMJPF2221.We also acknowledge the computer resources provided by the Academic Center for Computing and Media Studies(ACCMS)at Kyoto University and by the Research Center of Computer Science(RCCS)at the Institute for Molecular Science.
文摘The ground and excited state calculations at key geometries, such as the Frank–Condon (FC) and the conical intersection (CI)geometries, are essential for understanding photophysical properties. To compute these geometries on noisy intermediate-scalequantum devices, we proposed a strategy that combined a chemistry-inspired spin-restricted ansatz and a new excited statecalculation method called the variational quantum eigensolver under automatically-adjusted constraints (VQE/AC). Unlike theconventional excited state calculation method, called the variational quantum deflation, the VQE/AC does not require the pre-determination of constraint weights and has the potential to describe smooth potential energy surfaces. To validate this strategy,we performed the excited state calculations at the FC and CI geometries of ethylene and phenol blue at the complete active spaceself-consistent field (CASSCF) level of theory, and found that the energy errors were at most 2 kcal mol−1 even on the ibm_kawasakidevice.
