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Updated: Apr 18, 2026
12:29
Optimization of Crystal Growth for Neutron Macromolecular Crystallography
Published on: March 13, 2021
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Mode-selective control of the crystal lattice
M Först1, R Mankowsky, A Cavalleri
1Max-Planck Institute for the Structure and Dynamics of Matter , Hamburg 22761, Germany.
Accounts of Chemical Research
|January 17, 2015
Summary
Scientists are now controlling material phase changes using selective optical excitation of vibrational modes. This technique, using mid-infrared femtosecond pulses, drives electronic and magnetic phase transitions in complex oxides and enhances superconductivity in cuprates.
Area of Science:
- Condensed matter physics
- Laser science
- Materials science
Background:
- Phase changes are typically induced by near-infrared or visible light from femtosecond lasers.
- Selective vibrational excitation offers a new pathway for controlling material properties.
- Complex oxides exhibit significant electronic and magnetic property changes with subtle structural modulations.
Purpose of the Study:
- To summarize recent advancements in controlling collective phase states in solids via mode-selective lattice excitation.
- To present the theoretical framework and experimental validation of nonlinear phononics for phase control.
- To explore the potential of this technique for material design.
Main Methods:
- Generating intense, tunable mid-infrared femtosecond laser pulses.
- Utilizing femtosecond optical spectroscopy.
- Employing ultrafast X-ray diffraction at a free electron laser.
Main Results:
- Demonstrated nonlinear coupling between driven infrared-active phonon modes and other Raman-active modes.
- Observed nonlinear phononic excitation leading to net crystal displacement and phase transitions.
- Induced insulator-to-metal transitions, charge/orbital order melting, and magnetic switching in complex oxides.
- Achieved transient structures with enhanced superconductivity in high-TC cuprates.
Conclusions:
- Mode-selective lattice excitation via nonlinear phononics offers a powerful method for controlling material phases.
- This approach can drive diverse electronic and magnetic phase transitions in complex oxides.
- Combining nonlinear phononics with ultrafast X-ray crystallography provides new design principles for equilibrium materials with exotic properties.
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