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Despite exhibiting ferroelectric features, SrTiO₃ fails to display long-range polar order at low temperatures due to quantum fluctuations. An ultrafast X-ray diffraction experiment now probes polar dynamics of this material at the nanometre scale.

Superconductivity is studied in the molecular solid K₃C₆₀ when it is pressurized and illuminated with short laser pulses. Similarities with the non-illuminated case show that superconductivity exists at higher temperatures than previously thought.

Ultrashort mid-infrared laser pulses can drive atoms far from their equilibrium positions in LiNbO₃, exciting high phonon harmonics and providing a way to map the interatomic potential.

By exciting high-temperature K₃C₆₀ with mid-infrared pulses, a large increase in carrier mobility is obtained, accompanied by the opening of a gap in the optical conductivity; these same signatures are observed at equilibrium when cooling K₃C₆₀ below the superconducting transition temperature of 20 kelvin, which could be an indication of light-induced high-temperature superconductivity.

Femtosecond X-ray diffraction and ab initio density functional theory calculations are used to determine the crystal structure of YBa₂Cu₃O_6.5 undergoing optically driven, nonlinear lattice excitation above the transition temperature of 52 kelvin, under which conditions the electronic structure of the material changes in such a way as to favour superconductivity.

By measuring terahertz photon echoes, multidimensional spectroscopy demonstrates that interlayer tunnelling in a cuprate superconductor remains largely unaffected by electronic disorder, even near the phase transition.

Previous studies have suggested that even in the absence of a graphene bandgap, a relaxation bottleneck at the Dirac point may allow for population inversion and lasing. Now, using time- and angle-resolved photoemission spectroscopy with femtosecond extreme-ultraviolet pulses, it is shown that interband excitations give rise to population inversion, suggesting that terahertz lasing may be possible.

The authors analyze rare coding variants in 1990 individuals with congenital kidney anomalies, finding diagnostic variants in 14.1% of cases. They identify two new causal genes, ARID3A and NR6A1, along with 38 candidate genes, providing evidence for shared genetics with other developmental disorders.

The authors report ultrafast transport measurements on the photo-excited superconducting state in K₃C₆₀. They observe characteristic superconducting nonlinear current-voltage responses.

There is evidence that K₃C₆₀ can host a photo-induced superconducting state. Now, resonant excitation at low frequencies allows this phenomenon at room temperature and low pumping fluence.

Nonlinear phononics is a method for creating transient structural changes in solids, but its effect is limited to the region of optical excitation. Now, coupling to a propagating polariton allows nonlinear phononics to drive a nonlocal response.

Ultrafast magnetic field steps are generated by light-induced quenching of supercurrents in a YBa₂Cu₃O₇ superconductor. They exhibit millitesla amplitude, picosecond rise times and slew rates approaching 1 GT s^–1.

Mode-selective vibrational excitations can be used to transiently induce a range of phenomena in strongly correlated states of matter. It is now shown that by exciting apical oxygen distortions in the cuprate system YBa₂Cu₃O_6.5, an unusual photoconductive effect is induced both at low and at high temperatures.

Josephson plasma solitons are a kind of excitation predicted to occur in cuprate superconductors subject to strong electromagnetic fields. By using intense radiation from a free-electron laser, these modes are now demonstrated experimentally in the copper oxide material La_1.84Sr_0.16CuO₄.

Light can be used to directly excite phonon modes in condensed matter. Simultaneously exciting several modes in an antiferromagnetic rare-earth orthoferrite drives behaviour that mimics the application of a magnetic field.

This paper shows how lattice distortions induced by a laser pulse can create a ferrimagnetic moment in an antiferromagnet. This mechanism gives a magnetic response that is orders of magnitude larger than using mechanical strain.

A time-dependent magnetic field expulsion was measured in optically driven YBa₂Cu₃O_6.48 above the equilibrium superconducting transition temperature and all the way to room temperature. 

Intense light pulses can induce symmetry breaking, as for the generation of ferroelectricity in SrTiO₃. Using ultrafast X-ray diffuse scattering at a free-electron laser, nonlinear phonon interactions that occur on such mid-IR excitation are observed, with a theory for the dynamics presented.

A transient topological response in graphene is driven by a short pulse of light. When the Fermi energy is in the predicted band gap the Hall conductance is around two conductance quanta. An ultrafast detection technique enables the measurement.

Light can interact with the electrons in a crystalline solid, which in turn generates lattice vibrations or phonons. A related phenomenon was proposed 40 years ago in which it is the ions in the crystal rather than the electrons that mediate the interaction. This effect, known as ionic Raman scattering, is now observed experimentally.

Scientists demonstrate that strong single-cycle terahertz pulses can switch off interlayer superconductivity in a cuprate superconductor while leaving in-plane superconductivity unaltered. The effect may prove useful for studying and controlling the behaviour of future ultrafast nanoelectronics.

Ultrafast spectroscopy reveals the many-body effects behind the metallization of a one-dimensional Mott insulator. Unlike in ultracold gases, these femtosecond excitation studies of quantum dynamics occur at room temperature.

The origins and antiquity of the people of Europe has been much debated. Here, the authors sequence 3.7 Mb of the Y chromosome in over 300 Europeans and Middle Easterners and show a recent, continent-wide and male-specific expansion dating back to the Bronze Age.

All-optical, mode-selective manipulation of the crystal lattice can be used to enhance and stabilize ferromagnetism in YTiO₃ well above its equilibrium ordering temperature and for many nanoseconds, enabling dynamic engineering of practically useful non-equilibrium functionalities in fluctuating electronic systems.

Ultrafast pulses of terahertz radiation are used to excite individual vibrational modes in a magnetoresistive manganite. In a system such as this, with strongly correlated electrons, even subtle changes of crystal structure can have a profound effect on material properties, and this is indeed what they see: the activated vibration is sufficient to drive the material from a stable insulating phase to a metastable metallic one.

The control over phase transitions in complex oxides offers the possibility to control their electronic and structural properties. The discovery of a new route to ultrafast photoswitching of manganites via high-energy ‘hidden’ excited states offers the possibility of phase transitions free from thermal effects.

High-speed imaging gives us a fascinating insight into ultrafast changes in materials. By combining the speed of optical pulses and the short wavelength of X-ray pulses, imaging with 50-nm spatial and 10-ps temporal resolution is possible, with scope to go much further.

The observation that atomic disorder emerges exceptionally fast during laser-induced melting of crystalline bismuth prompts fresh thinking about the nature of this phase transition.

Evidence for light-induced superconductivity in K₃C₆₀ was limited to optical methods due to the short lifetime of the phase. Extending the lifetime from picoseconds to nanoseconds now allows measurement of its negligible electrical resistance.

By cunningly diffracting X-rays twice from an exploding nanometre-scale sphere, holographic images can be made of a tiny system evolving at lightning speed. The technique could be used to picture atomic dynamics.

Epilepsy is a brain network disorder with associated genetic risk factors. Here, the authors show that spatial patterns of transcriptomic vulnerability co-vary with structural brain network alterations in focal and generalized epilepsy.

In this largest whole-exome sequencing study of epilepsies to date, the Epi25 Collaborative identified extremely rare variants that confer risk for diverse epilepsy subtypes, highlighting roles in synaptic transmission and neuronal excitability.

Josephson plasma waves — electromagnetic waves propagating between layered superconductors — lie at the basis of a broad variety of phenomena. Now, parametric amplification of such waves has been shown by tuning the phase between pump and seed waves.

Here, the authors perform a meta-analysis in 26,699 people with seizures and 492,324 controls to identify 25 genome-wide significant copy-number variants. The discovered loci point to known disease genes and associations with clinical annotations.

The interaction between light and the crystal lattice of a quantum material can modify its properties. Utilizing nonlinear interactions allows this to be done in a controlled way to design specific non-equilibrium functionalities.

A spectroscopic study shows that vibrational pumping can be used to coherently control optical d–d transitions of electronic origin in the transition metal oxide system CuGeO₃.

A theoretical framework for interpreting recent observations of light-induced superconductivity in alkali-doped fullerides is proposed and developed.

The authors defined a roadmap for investigating the genetic covariance between structural or functional brain phenotypes and risk for psychiatric disorders. Their proof-of-concept study using the largest available common variant data sets for schizophrenia and volumes of several (mainly subcortical) brain structures did not find evidence of genetic overlap.