Themed collection From optical to THz control of materials
List of participants
Concluding remarks: Directing and controlling materials and molecules
Controlling materials, especially quantum materials, is a key goal of physical science. Biology provides inspiration for control of materials and molecules via feedback loops.
Local excitation and valley polarization in graphene with multi-harmonic pulses
Excitation in the valley domains of graphene, around K (warm colors) and K′ (cold colors) are induced by vertically-polarized multi-harmonic pulses (here containing ω and 2ω) with a maximum vector potential matching the distance K–K′.
Nonequilibrium dynamics of α-RuCl3 – a time-resolved magneto-optical spectroscopy study
We present time-resolved magneto-optical spectroscopy on the magnetic Mott–Hubbard-insulating Kitaev spin liquid candidate α-RuCl3 to investigate the nonequilibrium dynamics of its antiferromagnetically ordered zigzag groundstate after photoexcitation.
Spiers Memorial Lecture: From optical to THz control of materials
The concept of using appropriately shaped pulses of light to control the properties of materials has a range of potential applications, and relies on an understanding of intricate couplings within the material.
On the use of vibronic coherence to identify reaction coordinates for ultrafast excited-state dynamics of transition metal-based chromophores
Quantum coherences detected from ultrafast time-resolved absorption measurements are being explored to provide insight into the nature of the reaction coordinate for excited-state dynamics in transition metal complexes.
Visualizing optically-induced strains by five-dimensional ultrafast electron microscopy
Optically-induced nanoscale strain dynamics in nano-fabricated Si thin films are quantitatively visualized on the picosecond scale. A newly developed ultrafast five-dimensional convergent beam electron diffraction method is introduced.
Ultrafast branching in intersystem crossing dynamics revealed by coherent vibrational wavepacket motions in a bimetallic Pt(II) complex
Herein, we investigate the coherent vibrational wavepacket dynamics during the intersystem crossing processes in a bimetallic Pt(II) complex.
Signatures of collective modes in fifth harmonic generation of BCS superconductor
The fifth harmonic generated current in the BCS superconductor with a double peak signature. The resonant contributions describe the coupling of collective excitations with 2 and 4 photons. The processes are shown diagrammatically as insets.
Modelling nonlocal nonlinear spin dynamics in antiferromagnetic orthoferrites
We calculate nonlinear magnetic dynamics induced by an intense THz pulse in an antiferromagnet. As a result, we reveal an inhomogeneous switching regime involving moving domain walls and propagating magnons.
Quantum entanglement control of electron–phonon systems by light irradiation
The coherent control dynamics of interacting electron–phonon and qubit–spin systems is numerically studied. The time-evolution of the quantum many-body states is revealed from a viewpoint of quantum entanglement.
Ultrashort and metastable doping of the ZnO surface by photoexcited defects
We show exemplarily for the ZnO surface that photoexcited deep defects act like chemically doped shallow donors in semiconductors. Sufficiently strong “photodoping” makes ZnO a transient metal with influenceable ultrashort to metastable lifetimes.
Out-of-equilibrium dynamics driven by photoinduced charge transfer in CsCoFe Prussian blue analogue nanocrystals
Ultrafast optical and X-ray spectroscopies reveal the multiscale out-of-equilibrium dynamics in photoexcited CsCoFe Prussian blue analogue nanocrystals; from local charge-transfer to macroscopic crystal breathing.
Quench–drive spectroscopy of cuprates
We calculate the nonlinear signal of a cuprate superconductor when subjected to a quenching and a driving field, showing transient features of the generated higher harmonics, as well as the enhancement of coherence in incoherent Cooper pairs.
Ultrafast dynamics in (TaSe4)2I triggered by valence and core-level excitation
Time-resolved spectroscopy of (TaSe4)2I, which embeds different electronic structures, sheds light on out-of-equilibrium states driven by optical or X-ray excitation.
Signatures of coherent vibronic exciton dynamics and conformational control in the two-dimensional electronic spectroscopy of conjugated polymers
The computation of 2D electronic spectroscopy signals of intra-chain excitons reveals vibronic fine structure due to high-frequency polaronic modes, along with a dynamic Stokes shift induced by soft torsional modes, indicative of exciton motion.
Quantum dynamics simulations of the thermal and light-induced high-spin to low-spin relaxation in Fe(bpy)3 and Fe(mtz)6
We present a theoretical study of thermal and light-induced high-to-low spin crossover in prototypical Fe(II) complexes. We have computed the transfer rate of the HS state thermal relaxation at several time scales in two different iron complexes.
Ultrafast manipulation of the NiO antiferromagnetic order via sub-gap optical excitation
We present a comprehensive investigation of ultrafast demagnetisation and accompanying band gap reduction in a charge transfer insulator using time-resolved resonant X-ray reflectivity.
Impact of the terahertz and optical pump penetration depths on generated strain waves temporal profiles in a V2O3 thin film
Strain waves generated in pump probe experiments through thermoelastic interaction modulate transient optical transmission. Terahertz uniform or optical exponentially decaying pump profiles effects are investigated in metallic thin film V2O3.
THz non-linear optical response in cuprates: predominance of the BCS response over the Higgs mode
We compute the nonlinear current JNL induced by an intense THz field in superconducting cuprates. We find that JNL is dominated by the BCS response, showing comparable para- and diamagnetic contributions, in agreement with θ-resolved THG experiments.
Petahertz charge dynamics in a correlated organic superconductor
Unconventional stimulated emission and second harmonic generation (SHG) in an ultrafast no-scattering time window are induced by a nearly single-cycle 6 fs near infrared electric field of 10 MV cm−1 in an organic superconductor (κ-(h-ET)2Cu[N(CN)2]Br).
Attosecond electronic delay response in dielectric materials
Tracing the reflectivity modulation of a dielectric system in a strong field provides access to the electronic delay response of the system.
THz and laser field excitation processes: general discussion
Optical excitation processes: general discussion
Theory of out of equilibrium light-induced phenomena: general discussion
Material science: ultrafast transformation, electron–phonon coupling, multi-scale aspects: general discussion
About this collection
We are delighted to share with you a selection of the papers associated with a Faraday Discussion on From optical to THz control of materials. More information about the related event may be found here: http://rsc.li/control-fd2022. Additional articles will be added to the collection as they are published. The final versions of all the articles presented and a record of the discussions will be published after the event.
Ultrafast science has been for long limited to the investigation of molecular processes. Over the past 10 years, investigation of ultrafast processes has expanded to material science, with specific aspects related to solid-state like excitation of electron in band structures, collective phonon excitation, or specific probes for electronic and structural reorganization such as X-ray diffraction or ARPES. The meeting will cover 4 main themes: Material science: ultrafast transformation, electron-phonon coupling, multi-scale aspects, Theory of out of equilibrium light-induced phenomena, Optical excitation processes and THz and laser field excitation processes.
On behalf of the Scientific Committee, we hope you join us and participate in this exciting event, and that you enjoy these articles and the record of the discussion.