Coherent Phonon Catalysts: Lattice Vibrations Drive a Photoinduced **Phase** **Transition** in a Molecular Crystal

**phase**

**transitions**. Expand abstract.

**phase**

**transitions**. Discriminating between spectator and driving motions is a significant challenge hindering optimization. Unlocking this information and developing fine-tuned controls over actively participating phonon modes would not only lead to a stronger understanding of photochemistry but also provide a significant new tool in controlling solid-state chemistry. We present a strategy using rationally-designed double pulses to enhance the yield of a photoinduced

**phase**

**transition**in a molecular crystal through coherent control of individual phonons. Using ultrafast spectroscopy, we identified 50 cm-1 and 90 cm-1 phonons responsible for the photoinduced spin-Peierls melting of potassium tetracyanoquinodimethane crystals. We show that the 90 cm-1 phonon can be used to catalyze the

**phase**

**transition**process while the 50 cm-1 phonon enhances the yield of the initial charge transfer reaction.

10/10 relevant

chemRxiv

Sharp interface limit of a multi-**phase** **transitions** model under
nonisothermal conditions

6/10 relevant

arXiv

Information geometry of scaling expansions of non-exponentially growing confifiguration spaces

**transitions**between statistical manifolds corresponding to different families of probability distributions. Expand abstract.

**phase**

**transition**for the curvature. The

**phase**

**transition**can be well measured by the characteristic length r, corresponding to a ball with radius 2r having the same curvature as the statistical manifold. Increasing characteristic length with respect to the size of the system is associated with sub-exponential sample space growth is associated with strongly constrained and correlated complex systems. Decreasing of the characteristic length corresponds to super-exponential sample space growth that occurs for example in systems that develop structure as they evolve. Constant curvature means exponential sample space growth that is associated with multinomial statistics, and traditional Boltzmann-Gibbs, or Shannon statistics applies. This allows us to characterize

**transitions**between statistical manifolds corresponding to different families of probability distributions.

5/10 relevant

arXiv

Anisotropic character of the metal-to-metal **transition** in
Pr4Ni$_3$O$_{10}$

**phase**

**transition**at Tpt = 157 K has been revealed by previous studies, a comprehensive study of physical properties associated with this

**transition**has not yet been performed. We have grown single crystals of Pr4Ni3O10 at high oxygen pressure, and report on the physical properties around that

**phase**transition, such as heat-capacity, electric-transport and magnetization. We observe a distinctly anisotropic behavior between in-plane and out-of-plane properties: a metal-to-metal

**transition**at Tpt within the a-b plane, and a metal-to-insulator-like

**transition**along the c-axis with decreasing temperature. Moreover, an anisotropic and anomalous negative magneto-resistance is observed at Tpt that we attribute to a slight suppression of the first-order

**transition**with magnetic field. The magnetic-susceptibility can be well described by a Curie-Weiss law, with different Curie-constants and Pauli-spin susceptibilities between the high-temperature and the low-temperature

**phases**. The single crystal X-ray diffraction measurements show a shape variation of the different NiO6 octahedra from the high-temperature

**phase**to the low-temperature

**phase**. This subtle change of the environment of the Ni sites is likely responsible for the different physical properties at high and low temperatures.

7/10 relevant

arXiv

Upper limit on first-order electroweak **phase** **transition** strength

**transition**requirement puts an upper bound on the strength of the first-order

**phase**transition. Expand abstract.

**phase**transition, requiring no sphaleron washout of baryon number violating processes leads to a lower bound on the strength of the

**transition**. The

**phases**interface, the so-called bubble wall, velocity can become ultra-relativistic if the friction on the wall due to primordial plasma of particles surrounding it is not sufficient to retard the wall acceleration down to a steady speed. This bubble "runs away" should not occur if a successful baryon asymmetry generation due to the

**transition**is required. Using Boedeker-Moore criterion for bubble wall runaway, within the context of an extension of the standard model of particle physics with a real gauge-single scalar field, we show that a non runaway

**transition**requirement puts an upper bound on the strength of the first-order

**phase**

**transition**.

10/10 relevant

arXiv

Tricritical physics in two-dimensional $p$-wave superfluids

**phase**

**transitions**between superfluids and zero density vacuum are continuous. When strong quantum fluctuations near resonance are taken into account, the line of continuous

**phase**

**transitions**terminates at two multicritical points near resonance, between which the

**transitions**are expected to be first-order ones. The size of the window where first-order

**phase**

**transitions**occur is shown to be substantial when the coupling is strong. Near first-order transitions, superfluids self-contract due to

**phase**separations between superfluids and vacuum.

4/10 relevant

arXiv

Layer-Magnetization-Tuned Topological **Phases** in Mn$_2$Bi$_2$Te$_5$ Films

**phases**with exotic topological quantization phenomena, such as quantum anomalous Hall (QAH) insulators and axion insulators (AxI). Here by combining analytic models and first-principles calculations, we predict QAH and AxI

**phases**can be realized in thin film of an intrinsic antiferromagnetic van der Waal material Mn$_2$Bi$_2$Te$_5$. The

**phase**

**transition**between QAH and AxI is tuned by the layer magnetization, which would provide a promising platform for chiral superconducting

**phases**. We further present a simple and unified continuum model that captures the magnetic topological features, and is generic for Mn$_2$Bi$_2$Te$_5$ and MnBi$_2$Te$_4$ family materials.

5/10 relevant

arXiv

Transport signatures of topological **phases** in double nanowires probed by
spin-polarized STM

**phase**

**transition**that can be observed experimentally, for example, with an STM tip. Three bulk quantities, namely, the charge, the spin polarization, and the pairing amplitude of intrawire superconductivity are studied in this work. The spin polarization and the pairing amplitude flip sign as the system undergoes a

**phase**

**transition**from the trivial to the topological

**phase**. In order to identify promising ways to observe bulk signatures of the

**phase**

**transition**in transport experiments, we compute the spin current flowing between a local spin-polarized probe, such as an STM tip, and the double-nanowire system in the Keldysh formalism. We find that the spin current contains information about the sign flip of the bulk spin polarization and can be used to determine the topological

**phase**

**transition**point.

8/10 relevant

arXiv

On the diffusive-mean field limit for weakly interacting diffusions
exhibiting **phase** **transitions**

**phase**

**transition**, that is to say if it admits more than one steady state. Expand abstract.

**phase**transition, that is to say if it admits more than one steady state. A typical example of such a system on the torus is given by the noisy Kuramoto model of mean field plane rotators. As a by-product of our main results, we also analyse the energetic consequences of the central limit theorem for fluctuations around the mean field limit and derive optimal rates of convergence in relative entropy of the Gibbs measure to the (unique) limit of the mean field energy below the critical temperature.

9/10 relevant

arXiv

Intelligence, physics and information -- the tradeoff between accuracy and simplicity in machine learning

**phase**

**transitions**are predictable and reveal structure in the relationships between the data, the model, the learned representation and the loss landscape. Expand abstract.

**phase**

**transitions**in the two-term tradeoff, using strategies and tools from physics and information. Firstly, how can we make the learning models more flexible and efficient, so that agents can learn quickly with fewer examples? Inspired by how physicists model the world, we introduce a paradigm and an AI Physicist agent for simultaneously learning many small specialized models (theories) and the domain they are accurate, which can then be simplified, unified and stored, facilitating few-shot learning in a continual way. Secondly, for representation learning, when can we learn a good representation, and how does learning depend on the structure of the dataset? We approach this question by studying

**phase**

**transitions**when tuning the tradeoff hyperparameter. In the information bottleneck, we theoretically show that these

**phase**

**transitions**are predictable and reveal structure in the relationships between the data, the model, the learned representation and the loss landscape. Thirdly, how can agents discover causality from observations? We address part of this question by introducing an algorithm that combines prediction and minimizing information from the input, for exploratory causal discovery from observational time series. Fourthly, to make models more robust to label noise, we introduce Rank Pruning, a robust algorithm for classification with noisy labels. I believe that building on the work of my thesis we will be one step closer to enable more intelligent machines that can make sense of the world.

4/10 relevant

arXiv