Articles in 2023

de Broglie–Mackinnon wave packets are an extension of matter waves, but have so far remained a theoretical construct. Combining spatio-temporal light fields with anomalous dispersion has now allowed their experimental observation.

Dispersive coupling between two optical parametric oscillators induces a first-order phase transition in the system at a critical detuning. This manifests as a discontinuity in the dimer’s spectrum, which may be useful for enhanced sensing.

Superconductivity can emerge from a strange-metal state, but the exact relationship between them is unknown. Now, quantitative measurements reveal the dependence of resistivity in the strange metal on the superconducting transition temperature.

The transport behaviour of strange metals is distinct from weakly interacting Fermi liquids. Now, a large thermoelectric response has been shown at the transition between those two states.

Laboratory experiments reveal the underlying mechanism of turbulent reconnection, including electron acceleration. These findings are directly relevant for studies of flares in the solar corona.

Laboratory experiments demonstrate that electrons are accelerated to high energies by the reconnection electric field in magnetically driven reconnection. This mechanism is expected to be relevant for many astrophysical environments.

Second-order topological insulators feature helical one-dimensional states located at crystal hinges. Running a supercurrent through such systems is now shown to lead to long-lived excited Andreev pairs due to their separation along hinges with opposite helicity.

Time-crystalline order appears in periodically driven systems with broken time-translation symmetry. Now, a protocol based on pulse drives of different frequencies is used to create and continuously observe time crystals with long lifetimes.

Multi-parameter metrology requires collective measurements on more than one copy of the same quantum state. Now, an optimal scheme for the estimation of qubit rotations has been demonstrated on superconducting and trapped-ion platforms.

Interactions between photons arise due to the presence of optical nonlinearities. In topological Thouless pumps, a sufficiently strong nonlinearity leads to soliton transport with a fractionally quantized plateau structure—reminiscent of transport in the fractional quantum Hall effect.

Transport measurements between a normal conductor and superconductor show that in this case, the Coulomb drag response can be much larger than that between two normal conductors.

Topological defect structures that swim have been realized in liquid crystals. Now, a range of structures with topology reminiscent of a Möbius strip swim and transform into one another.

Quantum operations can be considered as points in a high-dimensional space in which distance reflects the similarity of two operations. Applying differential-geometric methods in this picture gives insights into the complexity of quantum systems.

Established methods of controlling silicon spin qubits require high-frequency signals that can be difficult to implement for various reasons. Exploiting the coupling between spin and valley degrees of freedom provides an alternative approach.

The renormalization group method is routinely employed in studies of criticality in many areas of physics. A framework based on a field theoretical description of information diffusion now extends this tool to the study of complex networks.

Superconducting currents around a loop containing a weak link can be quantized and only change during discrete events called phase slips. Now, the heat generated by a single phase slip and the subsequent relaxation have been experimentally observed.

Light could be used to carry quantum information in networks, but this requires methods to prepare and control individual photons. A superconducting circuit can controllably emit photons in either direction along a microwave waveguide.

Most temporal analyses of multivariate time series rely on pairwise statistics. A study combining network theory and topological data analysis now shows how to characterize the dynamics of signals at all orders of interactions in real-world data.