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Exploring Li-ion conductivity in cubic, tetragonal and mixed-phase Al-substituted Li7La3Zr2O12 using atomistic simulations and effective medium theory

Bonilla, M.R.; García Daza, F.A.; Carrasco, J.; Akhmatskaya, E.

(2019-08-15)

Garnet Li7La3Zr2O12 (LLZO) is a promising solid electrolyte candidate for solid-state Li-ion batteries, but at room temperature it crystallizes in a poorly Li-ion conductive tetragonal phase. To this end, partial substitution ...

Modified Hamiltonian Monte Carlo for Bayesian Inference

Radivojevic, T.; Akhmatskaya, E.

(2019-07-22)

The Hamiltonian Monte Carlo (HMC) method has been recognized as a powerful sampling tool in computational statistics. We show that performance of HMC can be significantly improved by incorporating importance sampling and ...

No Time at the End of the Tunnel

Sokolovski, D.; Akhmatskaya, E.

(2018-08-21)

Modern atto-second experiments seek to provide an insight into a long standing question: “how much time does a tunnelling particle spend in the barrier?” Traditionally, quantum theory relates this duration to the delay ...

Multi-stage splitting integrators for sampling with modified Hamiltonian Monte Carlo methods

Radivojevic, T.; Fernández-Pendás, M.; Sanz-Serna, J.M.; Akhmatskaya, E.

(2018-07-17)

Modified Hamiltonian Monte Carlo (MHMC) methods combine the ideas behind two popular sampling approaches: Hamiltonian Monte Carlo (HMC) and importance sampling. As in the HMC case, the bulk of the computational cost of ...

Revealing the Mechanism of Sodium Diffusion in NaxFePO4 Using an Improved Force Field

Bonilla, M.R.; Lozano, A.; Escribano, B.; Carrasco, J.; Akhmatskaya, E.

(2018-04-02)

Olivine NaFePO4 is a promising cathode material for Na-ion batteries. Intermediate phases such as Na0.66FePO4 govern phase stability during intercalation-deintercalation processes, yet little is known about Na+ diffusion ...

Atomistic Insight into Ion Transport and Conductivity in Ga/Al-Substituted Li$_7$La$_3$Zr$_2$O$_{12}$ Solid Electrolytes

García Daza, F.A.; Bonilla, M.R.; Llordés, A.; Carrasco, J.; Akhmatskaya, E.

(2018-01-09)

Garnet-structured Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$ is a promising solid electrolyte for next-generation solid-state Li batteries. However, sufficiently fast Li-ion mobility required for battery applications only emerges ...

An even simpler understanding of quantum weak values

Sokolovski, D.; Akhmatskaya, E.

(2018-01)

We explain the properties and clarify the meaning of quantum weak values using only the basic notions of elementary quantum mechanics.

Adaptive Splitting Integrators for Enhancing Sampling Efficiency of Modified Hamiltonian Monte Carlo Methods in Molecular Simulation

Akhmatskaya, E.

; Fernández-Pendás, M.; Radivojevic, T.; Sanz-Serna, J.M. (2017-10-24)

The modified Hamiltonian Monte Carlo (MHMC) methods, i.e., importance sampling methods that use modified Hamiltonians within a Hybrid Monte Carlo (HMC) framework, often outperform in sampling efficiency standard techniques ...

Reexamination of continuous fuzzy measurement on two-level systems

Sokolovski, D.; Rusconi, S.

; Brouard, S.; Akhmatskaya, E.

(2017-04-10)

Imposing restrictions on the Feynman paths of the monitored system has in the past been proposed as a universal model-free approach to continuous quantum measurements. Here we revisit this proposition and demonstrate that ...

Enhancing sampling in atomistic simulations of solid state materials for batteries: a focus on olivine NaFePO$_4$

Escribano, B.; Lozano, A.; Radivojevic, T.; Fernández-Pendás, M.; Carrasco, J.; Akhmatskaya, E.

(2017-03-07)

The study of ion transport in electrochemically active materials for energy storage systems requires simulations on quantum-, atomistic- and meso-scales. The methods accessing these scales not only have to be effective but ...