Publications de Ana Akrap | EPFL Graph Search

Characterization of two electronic subsystems in cuprates through optical conductivity

Ana Akrap, Edoardo Martino, Neven Barisic

Understanding the physical properties of unconventional superconductors as well as of other correlated materials presents a formidable challenge. Their unusual evolution with doping, frequency, and temperature has frequently led to non-Fermi-liquid (non-FL ...

2023

Addressing shape and extent of Weyl cones in TaAs by Landau level spectroscopy

Ana Akrap

TaAs is a prime example of a topological semimetal with two types of Weyl nodes, W-1 and W-2, whose bulk signatures have proven elusive. We apply Landau level spectroscopy to crystals with multiple facets and identify-among other low-energy excitations bet ...

AMER PHYSICAL SOC2022

Synthesis of murunskite single crystals: A bridge between cuprates and pnictides

László Forró, Henrik Moodysson Rønnow, Ivica Zivkovic, Ana Akrap, Edoardo Martino, Konstantin Semeniuk, Trpimir Ivsic, Davor Tolj

Numerous contemporary investigations in condensed matter physics are devoted to high temperature (high-T-c) cuprate superconductors. Despite its unique effulgence among research subjects, the enigma of the high-T-c mechanism still persists. One way to adva ...

ELSEVIER2021

Mahan excitons in room-temperature methylammonium lead bromide perovskites

Majed Chergui, László Forró, Endre Horvath, Ana Akrap, Edoardo Baldini, Márton Kollár, Tania Palmieri

In a seminal paper, Mahan predicted that excitonic bound states can still exist in a semiconductor at electron-hole densities above the insulator-to-metal Mott transition. However, no clear evidence for this exotic quasiparticle, dubbed Mahan exciton, exis ...

Nature Publishing Group2020

Probing intraband excitations in ZrTe5: A high-pressure infrared and transport study

Helmuth Berger, Mathieu François Padlewski, Philip Johannes Walter Moll, Matthias Carsten Putzke, Ana Akrap, Edoardo Martino

Zirconium pentatetelluride, ZrTe5, shows remarkable sensitivity to hydrostatic pressure. In this work we address the high-pressure transport and optical properties of this compound, on samples grown by flux and chemical vapor transport. The high-pressure r ...

2020

Preferential out-of-plane conduction and quasi-one-dimensional electronic states in layered 1T-TaS2

László Forró, Alla Arakcheeva, Luka Ciric, Helmuth Berger, Philip Johannes Walter Moll, Andrea Pisoni, Ana Akrap, Matthias Carsten Putzke, Edoardo Martino, Konstantin Semeniuk

Layered transition metal dichalcogenides (TMDs) are commonly classified as quasi-two-dimensional materials, meaning that their electronic structure closely resembles that of an individual layer, which results in resistivity anisotropies reaching thousands. ...

2020

Structural Phase Transition and Bandgap Control through Mechanical Deformation in Layered Semiconductors 1T-ZrX2 (X = S, Se)

Oleg Yazyev, Helmuth Berger, Ana Akrap, Michele Pizzochero, Edoardo Martino, Kristians Cernevics, Konstantin Semeniuk

Applying elastic deformation can tune a material's physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favoring photogenerated charge separation and collection in optoelectronic devices. These ...

AMER CHEMICAL SOC2020

Optical conductivity of the type-II Weyl semimetal TaIrTe4

Ana Akrap, Konstantin Semeniuk

TaIrTe4 is an example of a candidate Weyl type-II semimetal with a minimal possible number of Weyl nodes. Four nodes are reported to exist in a single plane in k space. The existence of a conical dispersion linked toWeyl nodes has yet to be shown experimen ...

AMER PHYSICAL SOC2020

Nature of native atomic defects in ZrTe5 and their impact on the low-energy electronic structure

Oleg Yazyev, Helmuth Berger, Shengnan Zhang, Ana Akrap

Over the past decades, investigations of the anomalous low-energy electronic properties of ZrTe5 have reached a wide array of conclusions. An open question is the growth method's impact on the stoichiometry of ZrTe5 samples, especially given the very small ...

AMER PHYSICAL SOC2020

Low-energy excitations in type-II Weyl semimetal T-d-MoTe2 evidenced through optical conductivity

Ana Akrap

Molybdenum ditelluride, MoTe2, is a versatile material where the topological phase can be readily tuned by manipulating the associated structural phase transition. The fine details of the band structure of MoTe2, key to understanding its topological proper ...

AMER PHYSICAL SOC2020