Publications de Edoardo Baldini

Electron-phonon-driven three-dimensional metallicity in an insulating cuprate

Cédric Weber, Fabrizio Carbone, Edoardo Baldini

The role of the crystal lattice for the electronic properties of cuprates and other high-temperature superconductors remains controversial despite decades of theoretical and experimental efforts. While the paradigm of strong electronic correlations suggest ...

National Academy of Sciences2020

Mahan excitons in room-temperature methylammonium lead bromide perovskites

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

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

Giant Exciton Mott Density in Anatase TiO2

Majed Chergui, Tania Palmieri, Edoardo Baldini

Elucidating the carrier density at which strongly bound excitons dissociate into a plasma of uncorrelated electron-hole pairs is a central topic in the many-body physics of semiconductors. However, there is a lack of information on the high-density respons ...

2020

Electron Dynamics in Anatase TiO2 Nanoparticles by Ultrafast Broadband Deep-Ultraviolet Spectroscopy

Majed Chergui, Gerald Auböck, Tania Palmieri, Edoardo Baldini, Enrico Pomarico

The optical bandgap of anatase TiO2 nanoparticles is dominated by bulk absorption bands in the deep-ultraviolet due to strongly bound excitons. These spectral features can be utilized as a sensitive probe of carrier and lattice dynamics inside the TiO2 nan ...

E D P SCIENCES2019

Exciton control in a room temperature bulk semiconductor with coherent strain pulses

Majed Chergui, Tania Palmieri, Edoardo Baldini, Oliviero Cannelli

Controlling the excitonic optical properties of room temperature semiconductors using time-dependent perturbations is key to future optoelectronic applications. The optical Stark effect in bulk and low-dimensional materials has recently shown exciton shift ...

American Association for the Advancement of Science (AAAS)2019

Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles

Majed Chergui, Gerald Auböck, Tania Palmieri, Edoardo Baldini, Enrico Pomarico

2018

Lattice-mediated magnetic order melting in TbMnO3

Fabrizio Carbone, Edoardo Baldini

Recent ultrafast magnetic-sensitive measurements [Johnson et al., Phys. Rev. B 92, 184429 (2015); Bothschafter et al., Phys. Rev. B 96, 184414 (2017)] have revealed a delayed melting of the long-range cycloid spin order in TbMnO 3 following photoexcitation ...

2018

Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2Nanoparticles

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as se ...

American Chemical Society (ACS)2018

Discovery and room-temperature ultrafast manipulation of strongly bound excitons in anatase TiO2

Majed Chergui, Tania Palmieri, Edoardo Baldini

AMER CHEMICAL SOC2018

Coherent generation of symmetry-forbidden phonons by light-induced electron-phonon interactions in magnetite

Frank van Mourik, Oleg Yazyev, Christopher Alexander Arrell, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni

Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. In second-order or weakly first-order tr ...

Amer Physical Soc2017

Anomalous anisotropic exciton temperature dependence in rutile TiO2

Majed Chergui, Edoardo Baldini

Elucidating the details of electron-phonon coupling in semiconductors and insulators is a topic of pivotal interest, as it governs the transport mechanisms and is responsible for various phenomena such as spectral-weight transfers to phonon sidebands and s ...

2017

Clocking the onset of bilayer coherence in a high-Tc cuprate

Frank van Mourik, Christopher Alexander Arrell, Dragan Mihailovic, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini

In cuprates, a precursor state of superconductivity is speculated to exist above the critical temperature T-c. Here we show via a combination of far-infrared ellipsometry and ultrafast broadband optical spectroscopy that signatures of such a state can be o ...

Amer Physical Soc2017

Nonequilibrium Dynamics of Collective Excitations in Strongly Interacting and Correlated Quantum Systems

Edoardo Baldini

Revealing the emergence and the dynamics of collective excitations in complex matter is a subject of pivotal importance, as it provides insight into the strength and spatial distribution of interactions and correlations. At the same time, collectivity lies ...

EPFL2017

Real-Time Observation of Phonon-Mediated σ−π Interband Scattering in MgB2

Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni, Ting Tan

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properti ...

2017

The LOUVRE Laboratory: State-of-the-Art Ultrafast Ultraviolet Spectroscopies for Molecular and Materials Science

Majed Chergui, Frank van Mourik, Natalia Nagornova, Lars-Hendrik Mewes, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Malte Oppermann, Benjamin Bauer, Aurelio Oriana

We describe the facilities for ultraviolet studies in the femtosecond to nanosecond time domain. These facilities consist of: i) a set-up for deep-ultraviolet spectroscopy in the 260–380 nm range in both pump and probe pulses for transient absorption/refle ...

2017

Strongly bound excitons in anatase TiO2 single crystals and nanoparticles

Helmuth Berger, Marco Grioni, Majed Chergui, Arnaud Magrez, Gerald Auböck, Simon Karl Moser, Edoardo Baldini

Anatase TiO2 is among the most studied materials for light-energy conversion applications, but the nature of its fundamental charge excitations is still unknown. Yet it is crucial to establish whether light absorption creates uncorrelated electron-hole pai ...

Nature Publishing Group2017

Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

Ultrafast interfacial electron transfer in sensitized solar cells has mostly been probed by visible-to-terahertz radiation, which is sensitive to the free carriers in the conduction band of the semiconductor substrate. Here, we demonstrate the use of deep- ...

2017

A versatile setup for ultrafast broadband optical spectroscopy of coherent collective modes in strongly correlated quantum systems

Frank van Mourik, Christopher Alexander Arrell, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni

A femtosecond pump-probe setup is described that is optimised for broadband tran- sient reflectivity experiments on solid samples over a wide temperature range. By combining high temporal resolution and a broad detection window, this apparatus can investig ...

2016

Probing the coupling between a doublon excitation and the charge-density wave in TaS2 by ultrafast optical spectroscopy

Helmuth Berger, Arnaud Magrez, Ahmad Odeh, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini

Recently, the switching between the different charge-ordered phases of 1T-TaS2 has been probed by ultrafast techniques, revealing unexpected phenomena such as "hidden" metastable states and peculiar photoexcited charge patterns. Here, we apply broadband pu ...

Amer Physical Soc2016

Probing the electron-phonon interaction in correlated systems with coherent lattice fluctuation spectroscopy

Frank van Mourik, Christopher Alexander Arrell, Fabrizio Carbone, Kazimierz Conder, Andreas Helmut Christian Mann, Edoardo Baldini

Tailoring the properties of correlated oxides is accomplished by chemical doping, pressure, temperature, or magnetic field. Photoexcitation is a valid alternative to reach out-of-equilibrium states otherwise inaccessible. Here, we quantitatively estimate t ...

Amer Physical Soc2015