Publications by Christopher Alexander Arrell

Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, José Javier Pancracio Ojeda Andara, Luca Longetti, Thomas Roland Barillot, Michele Puppin

The photochemistry of metal-organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation. Understanding its prime mechanisms is crucial to optimise the reactive paths and control their outcome. H ...

2021

A compact and cost-effective hard X-ray free-electron laser driven by a high-brightness and low-energy electron beam

Lukas Stingelin, Majed Chergui, Paul Beaud, Thomas Schietinger, Christopher Alexander Arrell, Thomas Schmidt, Leonid Rivkin, Christoph Peter Hauri, Giulia Fulvia Mancini, Rasmus Ischebeck, Eugenio Ferrari, Camila Bacellar Cases Da Silveira, Mike Seidel, Paolo Craievich, Sven Reiche

We present the first lasing results of SwissFEL, a hard X-ray free-electron laser (FEL) that recently came into operation at the Paul Scherrer Institute in Switzerland. SwissFEL is a very stable, compact and cost-effective X-ray FEL facility driven by a lo ...

Nature Publishing Group2020

Photoemission from non-polar aromatic molecules in the gas and liquid phase

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Lars-Hendrik Mewes, José Javier Pancracio Ojeda Andara, Jakob Grilj, Luca Longetti

The photoelectron spectra of both liquid and gas phase aromatic molecules are reported. The spectra were obtained using a 34.1 eV source produced by high harmonic generation and analysed with the help of high-level ab initio simulations using the reflectio ...

ROYAL SOC CHEMISTRY2020

Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies

Majed Chergui, Wojciech Gawelda, Christopher Alexander Arrell, Frederico Alves Lima, Giulia Fulvia Mancini, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Jérémy Raymond Jean Maurice Rouxel, Samuel Menzi

The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (C ...

National Academy of Sciences2020

Experimental station Bernina at SwissFEL: condensed matter physics on femtosecond time scales investigated by X-ray diffraction and spectroscopic methods

Paul Beaud, Christopher Alexander Arrell, Christoph Peter Hauri, Giulia Fulvia Mancini, Jochen Rittmann

The Bernina instrument at the SwissFEL Aramis hard X-ray free-electron laser is designed for studying ultrafast phenomena in condensed matter and material science. Ultrashort pulses from an optical laser system covering a large wavelength range can be used ...

International Union of Crystallography (IUCr)2019

The SwissFEL soft X-ray free-electron laser beamline: Athos

Thomas Schietinger, Christopher Alexander Arrell, Thomas Schmidt, Rasmus Ischebeck, Eugenio Ferrari, Christoph Bostedt, Paolo Craievich, Sven Reiche

The SwissFEL soft X-ray free-electron laser (FEL) beamline Athos will be ready for user operation in 2021. Its design includes a novel layout of alternating magnetic chicanes and short undulator segments. Together with the APPLE X architecture of undulator ...

2019

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

Harmonium: An Ultrafast Vacuum Ultraviolet Facility

Marco Grioni, Marcel Drabbels, Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Alberto Crepaldi, José Javier Pancracio Ojeda Andara, Andrew Daniel Bonnar Clark, Gianmarco Gatti, Luca Longetti, Silvan Dino Marcos Roth

Harmonium is a vacuum ultraviolet (VUV) photon source built within the Lausanne Centre for Ultrafast Science (LACUS). Utilising high harmonic generation, photons from 20-110 eV are available to conduct steady-state or ultrafast photoelectron and photoion s ...

Swiss Chemical Soc2017

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

Photoemission and photoionization time delays and rates

Majed Chergui, Ursula Röthlisberger, Christopher Alexander Arrell, Elisa Liberatore

2017

Time-resolved ARPES at LACUS: Band Structure and Ultrafast Electron Dynamics of Solids

Helmuth Berger, Philippe Bugnon, Marco Grioni, Majed Chergui, Frank van Mourik, Arnaud Magrez, Christopher Alexander Arrell, Alberto Crepaldi, José Javier Pancracio Ojeda Andara, Gianmarco Gatti, Silvan Dino Marcos Roth

The manipulation of the electronic properties of solids by light is an exciting goal, which requires knowledge of the electronic structure with energy, momentum and temporal resolution. Time- and angle-resolved photoemission spectroscopy (tr-ARPES) is the ...

2017

Charge migration and charge transfer in molecular systems

Jacques-Edouard Moser, Majed Chergui, Joël Teuscher, Ursula Röthlisberger, Christopher Alexander Arrell, Andrea Cannizzo, Pablo Lopez Tarifa, Natalie Renuka Banerji, Elisa Liberatore

The transfer of charge at the molecular level plays a fundamental role in many areas of chemistry, physics, biology and materials science. Today, more than 60 years after the seminal work of R. A. Marcus, charge transfer is still a very active field of res ...

2017

Charge-transfer and impulsive electronic-to-vibrational energy conversion in ferricyanide: ultrafast photoelectron and transient infrared studies'

Majed Chergui, Christopher Alexander Arrell, José Javier Pancracio Ojeda Andara, Luca Longetti

The photophysics of ferricyanide in H2O, D2O and ethylene glycol was studied upon excitation of ligand-to-metal charge transfer (LMCT) transitions by combining ultrafast photoelectron spectroscopy (PES) of liquids and transient vibrational spectroscopy. Up ...

Royal Society of Chemistry2017

Laser-Assisted Photoelectric Effect from Liquids

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Lars-Hendrik Mewes, José Javier Pancracio Ojeda Andara, Jakob Grilj

The laser-assisted photoelectric effect from liquid surfaces is reported for the first time. Photoelectrons generated by 35.6 eV radiation from a liquid microjet of water under vacuum are dressed with (h) over bar omega = 1.55 eV laser field. The subsequen ...

American Physical Society2016

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

Harmonium: A pulse preserving source of monochromatic extreme ultraviolet (30–110 eV) radiation for ultrafast photoelectron spectroscopy of liquids

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Hua Zhang, Lars-Hendrik Mewes, José Javier Pancracio Ojeda Andara, Jakob Grilj

A tuneable repetition rate extreme ultraviolet source (Harmonium) for time resolved photoelectron spectroscopy of liquids is presented. High harmonic generation produces 30-110 eV photons, with fluxes ranging from similar to 2 x 10(11) photons/s at 36 eV t ...

Amer Inst Physics2016

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

Temporal broadening of attosecond photoelectron wavepackets from solid surfaces

Christopher Alexander Arrell

The response of solids to electromagnetic fields is of crucial importance in many areas of science and technology. Many fundamental questions remain to be answered about the dynamics of the photoexcited electrons that underpin this response, which can evol ...

Optical Soc Amer2015

Set-up for broadband Fourier-transform multidimensional electronic spectroscopy

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Gerald Auböck, Andre Al Haddad, José Javier Pancracio Ojeda Andara, Adrien Alexis Paul Chauvet

We present a compact passively phase-stabilized ultra-broadband 2D Fourier transform setup. A gas (argon)-filled hollow core fiber pumped by an amplified Ti:Al2O3 laser is used as a light source providing spectral range spanning from 420 to 900 nm. Sub-10- ...

Optical Society of America2015

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, José Javier Pancracio Ojeda Andara

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preservi ...

Amer Inst Physics2014