Quantifying spatial correlations of general quantum dynamics

Understanding the role of correlations in quantum systems is both a fundamental challenge as well as of high practical relevance for the control of multi-particle quantum systems. Whereas a lot of research has been devoted to study the various types of correlations that can be present in the states of quantum systems, in this work we introduce a general and rigorous method to quantify the amount of correlations in the dynamics of quantum systems. Using a resource-theoretical approach, we introduce a suitable quantifier and characterize the properties of correlated dynamics. Furthermore, we benchmark our method by applying it to the paradigmatic case of two atoms weakly coupled to the electromagnetic radiation field, and illustrate its potential use to detect and assess spatial noise correlations in quantum computing architectures

Density-matrix Chern insulators: finite-temperature generalization of topological insulators

Thermal noise can destroy topological insulators (TI). However, we demonstrate how TIs can be made stable in dissipative systems. To that aim, we introduce the notion of band Liouvillian as the dissipative counterpart of band Hamiltonian, and show a method to evaluate the topological order of its steady state. This is based on a generalization of the Chern number valid for general mixed states (referred to as density-matrix Chern value), which witnesses topological order in a system coupled to external noise. Additionally, we study its relation with the electrical conductivity at finite temperature, which is not a topological property. Nonetheless, the density-matrix Chern value represents the part of the conductivity which is topological due to the presence of quantum mixed edge states at finite temperature. To make our formalism concrete, we apply these concepts to the two-dimensional Haldane model in the presence of thermal dissipation, but our results hold for arbitrary dimensions and density matrices

Two-dimensional density-matrix topological fermionic phases: topological Uhlmann numbers

We construct a topological invariant that classifies density matrices of symmetry-protected topological orders in two-dimensional fermionic systems. As it is constructed out of the previously introduced Uhlmann phase, we refer to it as the topological Uhlmann number n_(U). With it, we study thermal topological phases in several two-dimensional models of topological insulators and superconductors, computing phase diagrams where the temperature T is on an equal footing with the coupling constants in the Hamiltonian. Moreover, we find novel thermal-topological transitions between two nontrivial phases in a model with high Chern numbers. At small temperatures we recover the standard topological phases as the Uhlmann number approaches to the Chern number

Robust nonequilibrium surface currents in the three-dimensional Hofstadter model

Genuinely two-dimensional robust crosscurrents-which flow against the natural direction of heat flux- have been missing since the discovery of their one-dimensional counterpart. We provide a setup to realize them on a cubic three-dimensional (3D) lattice hosting a Hofstadter model coupled to two heat baths with different temperatures. We show that these currents exhibit dissipative robustness; they are stable against the presence of impurities and tilting of the gauge field in certain nonequilibrium configurations. Moreover, we find protected boundary currents with genuinely 3D robustness, i.e., they are only stable if tunneling can occur in all three spatial directions. The model also presents generic surface currents, which are robust for both bosonic and fermionic systems. We identify the underlying qualitative mechanism responsible for the robustness of the surface currents and the crucial role played by certain discrete symmetries

Thermal instability of protected end states in a one-dimensional topological insulator

We have studied the dynamical thermal effects on the protected end states of a topological insulator (TI) when it is considered as an open quantum system in interaction with a noisy environment at a certain temperature T . As a result, we find that protected end states in a TI become unstable and decay with time. Very remarkably, the interaction with the thermal environment (fermion-boson) respects chiral symmetry, which is the symmetry responsible for the protection (robustness) of the end states in this TI when it is isolated from the environment. Therefore, this mechanism makes end states unstable while preserving their protecting symmetry. Our results have immediate practical implications in recently proposed simulations of TIs using cold atoms in optical lattices. Accordingly, we have computed lifetimes of topological end states for these physical implementations that are useful to make those experiments realistic

Métodos Matemáticos de la Física y la Música

Esta documento corresponde a la memoria final de ejecución del proyecto de innovación docente número 216 de la convocatoria 2019/2020 que lleva por título "Métodos Matemáticos de la Física y la Música"

Física, Matemáticas y Música

Esta documento corresponde a la memoria final de ejecución del proyecto de innovación docente número 210 de la convocatoria 2020/2021 que lleva por título "Física, Matemáticos y Música"

KRas4BG12C/D/PDE6δ Heterodimeric Molecular Complex: A Target Molecular Multicomplex for the Identification and Evaluation of Nontoxic Pharmacological Compounds for the Treatment of Pancreatic Cancer

The search for new targeted therapies to improve the quality of life of patients with pancreatic cancer has taken about 30 years. Compounds that can inhibit the K-Ras4B oncoprotein signaling pathway have been sought. Taking into account that the interaction of KRas4B with PDE6δ is essential for its transport and subsequent activation in the plasma membrane, our working group identified and evaluated in vitro and in vivo small organic molecules that could act as molecular staples to stabilize the KRas4B/PDE6δ heterodimeric complex. From this group of molecules, 38 compounds with high interaction energies on the structure of the crystallized molecular complex were selected, indicating that they efficiently stabilized the molecular complex. In vitro evaluation of compounds called D14, C22, and C19 showed significant specific effects on the cell viability of pancreatic cancer cells (and not on normal cells), thus inducing death by apoptosis and significantly inhibiting the activation of the pathways, signaling AKT and ERK. In addition to these experimental findings, we were also able to detect that compounds D14 and C22 showed significant tumor growth inhibitory activity in pancreatic cancer cell-induced subcutaneous xenograft models

TRAF3 alterations are frequent in del-3′IGH chronic lymphocytic leukemia patients and define a specific subgroup with adverse clinical features

Interstitial 14q32 deletions involving IGH gene are infrequent events in chronic lymphocytic leukemia (CLL), affecting less than 5% of patients. To date, little is known about their clinical impact and molecular underpinnings, and its mutational landscape is currently unknown. In this work, a total of 871 CLLs were tested for the IGH break-apart probe, and 54 (6.2%) had a 300 kb deletion of 3′IGH (del-3′IGH CLLs), which contributed to a shorter time to first treatment (TFT). The mutational analysis by next-generation sequencing of 317 untreated CLLs (54 del-3′IGH and 263 as the control group) showed high mutational frequencies of NOTCH1 (30%), ATM (20%), genes involved in the RAS signaling pathway (BRAF, KRAS, NRAS, and MAP2K1) (15%), and TRAF3 (13%) within del-3′IGH CLLs. Notably, the incidence of TRAF3 mutations was significantly higher in del-3′IGH CLLs than in the control group (p < .001). Copy number analysis also revealed that TRAF3 loss was highly enriched in CLLs with 14q deletion (p < .001), indicating a complete biallelic inactivation of this gene through deletion and mutation. Interestingly, the presence of mutations in the aforementioned genes negatively refined the prognosis of del-3′IGH CLLs in terms of overall survival (NOTCH1, ATM, and RAS signaling pathway genes) and TFT (TRAF3). Furthermore, TRAF3 biallelic inactivation constituted an independent risk factor for TFT in the entire CLL cohort. Altogether, our work demonstrates the distinct genetic landscape of del-3′IGH CLL with multiple molecular pathways affected, characterized by a TRAF3 biallelic inactivation that contributes to a marked poor outcome in this subgroup of patients.Funding information: Universidad de Salamanca; Fundación Española de Hematología y Hemoterapia (FEHH); Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Grant/Award Number: CB16/12/00233; Red Temática de Investigación Cooperativa en Cáncer (RTICC); “Fundación Memoria Don Samuel Solórzano Barruso”: FS/33–2020, Grant/Award Number: RD12/0036/0069; “Gerencia Regional de Salud, SACYL”:, Grant/Award Numbers: GRS2385/A/21, GRS2140/A/20; Consejería de Educación, Junta de Castilla y León, Grant/Award Number: SA118P20; European Regional Development Fund and Instituto de Salud Carlos III, Grant/Award Numbers: CD19/00222, FI19/00191; Spanish Fondo de Investigaciones Sanitarias, Grant/Award Numbers: PI21/00983, PI18/0150