Determining the Continuous Family of Quantum Fisher Information from Linear Response Theory

The quantum Fisher information represents the continuous family of metrics on the space of quantum states and places the fundamental limit on the accuracy of quantum state estimation. We show that the entire family of the quantum Fisher information can be determined from linear response theory through generalized covariances. We derive the generalized fluctuation-dissipation theorem that relates the linear response function to generalized covariances and hence allows us to determine the quantum Fisher information from linear response functions, which is experimentally measurable quantities. As an application, we examine the skew information, which is one of the quantum Fisher information, of a harmonic oscillator in thermal equilibrium, and show that the equality of the skew information-based uncertainty relation holds.Comment: 8 pages, 1 figur

Efficient determination of alloy ground-state structures

We propose an efficient approach to accurately finding the ground-state structures in alloys based on the cluster expansion method. In this approach, a small number of candidate ground-state structures are obtained without any information of the energy. To generate the candidates, we employ the convex hull constructed from the correlation functions of all possible structures by using an efficient algorithm. This approach is applicable to not only simple lattices but also complex lattices. Firstly, we evaluate the convex hulls for binary alloys with four types of simple lattice. Then we discuss the structures on the vertices. To examine the accuracy of this approach, we perform a set of density functional theory calculations and the cluster expansion for Ag-Au alloy and compare the formation energies of the vertex structures with those of all possible structures. As applications, the ground-state structures of the intermetallic compounds CuAu, CuAg, CuPd, AuAg, AuPd, AgPd, MoTa, MoW and TaW are similarly evaluated. Finally, the energy distribution is obtained for different cation arrangements in MgAl$_2$O$_4$ spinel, for which long-range interactions are essential for the accurate description of its energetics.Comment: 8 pages, 7 figure

Potential P-Glycoprotein-Mediated Drug-Drug Interactions of Antimalarial Agents in Caco-2 cells

Antimalarials are widely used in African and Southeast Asian countries, where they are combined with other drugs for the treatment of concurrent ailments. The potential for P-glycoprotein (P-gp)-mediated drug-drug interactions (DDIs) between antimalarials and P-gp substrates was examined using a Caco-2 cell-based model. Selected antimalarials were initially screened for their interaction with P-gp based on the inhibition of rhodamine-123 (Rho-123) transport in Caco-2 cells. Verapamil (100 mM) and quinidine (1 mM) were used as positive inhibition controls. Lumefantrine, amodiaquin, and artesunate all showed blockade of Rho-123 transport. Subsequently, the inhibitory effect of these antimalarials on the bi-directional passage of digoxin (DIG) was examined. All of the drugs decreased basal-toapical (B-A) P-gp-mediated DIG transport at concentrations of 100 mM and 1 mM. These concentrations may reflect therapeutic doses for amodiaquin and artesunate. Therefore, clinically relevant DDIs may occur between certain antimalarials and P-gp substrates in general