Quantum gases of light, such as photon or polariton condensates in optical microcavities, are collective quantum systems enabling a tailoring of dissipation from, for example, cavity loss. This characteristic makes them a tool to study dissipative phases, an emerging subject in quantum many-body physics. We experimentally demonstrate a non-Hermitian phase transition of a photon Bose-Einstein condensate to a dissipative phase characterized by a biexponential decay of the condensate's second-order coherence. The phase transition occurs because of the emergence of an exceptional point in the quantum gas. Although Bose-Einstein condensation is usually connected to lasing by a smooth crossover, the observed phase transition separates the biexponential phase from both lasing and an intermediate, oscillatory condensate regime. Our approach can be used to study a wide class of dissipative quantum phases in topological or lattice systems.

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.abe9869DOI Listing

Publication Analysis

Top Keywords

phase transition
16
non-hermitian phase
8
quantum gas
8
phase
6
quantum
6
observation non-hermitian
4
transition
4
transition optical
4
optical quantum
4
gas quantum
4

Similar Publications

Traditionally, multiple shape memory polymers (multiple-SMPs) are created by forming either immiscible blends with high phase continuity (cocontinuous or multilayer phase morphology) or miscible blends that exhibit compositional heterogeneity at the nanoscale. Here, a new strategy for the fabrication of multiple-SMPs is proposed. It consists of the possibility of homogeneous mixing of immiscible polymers in the solid state under high pressure and shear deformation conditions.

View Article and Find Full Text PDF

Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), an experimental and theoretical study of changes in the electronic structure (dispersion dependencies) and corresponding modification of the energy band gap at the Dirac point (DP) for topological insulator (TI) [Formula: see text] have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from 10% to 75%. It was shown that when Ge concentration increases, the bulk band gap decreases and reaches zero plateau in the concentration range of 45-60% while trivial surface states (TrSS) are present and exhibit an energy splitting of 100 and 70 meV in different types of measurements. It was also shown that TSS disappear from the measured band dispersions at a Ge concentration of about 40%.

View Article and Find Full Text PDF

Prospects of cowpea protein as an alternative and natural emulsifier for food applications: Effect of pH and oil concentration.

Int J Biol Macromol

January 2025

Department of Food Engineering and Technology, Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (UNESP), Street Cristóvão Colombo, 2265, São José do Rio Preto 15054-000, Brazil. Electronic address:

In response to the growing need to expand the knowledge base on novel, more sustainable protein sources, this study investigated the effectiveness of cowpea protein concentrate (CPC) as a natural emulsifying agent, examining the relationships between pH (3-11), oil concentration (2-10 %), and emulsion stability. pH and oil concentration significantly impacted droplet size distribution, with uniformity decreasing in the order of pH 9 > pH 11 > pH 7, which was attributed to droplet coalescence and flocculation. As evidenced by circular dichroism, alkalinity induced a slight increase in the beta-sheet content of CPC, while simultaneously reducing the alpha-helix content.

View Article and Find Full Text PDF

Design and synthesis of autogenous growth NiFe bimetallic phosphide catalysts on a nickel iron foam-like substrate for efficient overall water splitting.

J Colloid Interface Sci

January 2025

Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province, School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, PR China. Electronic address:

The design of low-cost, highly active, and stable electrocatalysts is pivotal for advancing water electrolysis technologies. In this study, carbonyl iron powder (CIP) was anchored within the pores of nickel foam (NF) by electroplating nickel, creating nickel iron foam-like (NFF-L) substrates. Subsequently, nickel-iron hydroxide (NiFe-OH) was synthesized on the NFF-L substrate employing an autogenous growth strategy, followed by a phosphating treatment that produced a nanoflower-like NiFe bimetallic phosphide heterostructure catalyst (FeP-NiP@NFF-L).

View Article and Find Full Text PDF

Lipid nanoparticles formed with copolymers are a new and increasingly powerful tool for studying membrane proteins, but the extent to which these systems affect the physical properties of the membrane is not completely understood. This is critical to understanding the caveats of these new systems and screening for structural and functional artifacts that might be caused in the membrane proteins they are used to study. To better understand these potential effects, the fluid properties of dipalmitoylphosphatidylcholine lipid bilayers were examined by electron paramagnetic resonance (EPR) spectroscopy with spin-labeled reporter lipids in either liposomes or incorporated into nanoparticles with the copolymers diisobutylene-maleic acid or styrene maleic acid.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!