2026

As minimal cells or protocells are dramatically simpler than modern unicells it is possible to quantitatively estimate free energy changes for every process in the lifecycle of a protocell and compare these with estimates of the free energy changes for lifecycles in modern unicells. We present quantitative estimates of all metabolic changes in part by new density function theory (DFT) estimations, in part by compiling previously measured or estimated free energy changes, and in part by new thermodynamic calculations for all self-assembly, vesicle bending, and fission energies.

Open-shell nanographenes offer a controlled setting to study correlated magnetism emerging from π-electron systems. We analyze oligo(indenoindene) molecules, non-bipartite carbon ladders whose tight-binding spectra feature a gapped, weakly dispersing manifold of quasi-zero modes, and show that their low-energy properties can be effectively mapped onto an interacting set of spin-1/2 degrees of freedom. Using Density Matrix Renormalization Group simulations of the full Fermi-Hubbard model, we obtain their excitation spectra, entanglement profiles, and spin-spin correlations. We then construct optimized delocalized fermionic modes that act as emergent spins and show that their interactions are well described by a frustrated J₁-J₂ Heisenberg chain. This effective description clarifies how spin degrees of freedom arise and interact in non-bipartite nanographene ladders, providing a compact and accurate representation of their correlated behavior.

Open-shell nanographenes provide a versatile platform to host unconventional magnetic states within their π-conjugated networks. Particularly appealing are graphene architectures that incorporate spatially separated radicals and tunable interactions, offering a scalable route toward spin-based quantum architectures. Triangulenes are ideal for this purpose, as their radical count scales with size, although strong hybridization prevents individual spin control. Here, we realize a radical reconfiguration strategy that transforms a single-radical aza-triangulene into a frustrated antiferromagnetic triradical by covalently extending it with armchair anthene moieties of increasing length. Scanning tunnelling spectroscopy reveals edge-localized Kondo resonances and a doublet-to-quartet spin excitation, evidencing the emergence of correlated spins. Multi-reference electronic-structure calculations trace the progressive increase in polyradical character with anthene length, driven by the clustering of frontier states within a narrow energy window. Consequently, the initial single-radical doublet reorganizes into a frustrated triradical with weakly coupled edge spins, a molecular analog of a three-qubit quantum register.

We develop a microscopic model to investigate current-induced light emission in single-molecule tunnel junctions, where a two-level system interacts with a plasmonic field. Using the quantum master equation, we explore the transition from weak to strong plasmon-molecule coupling, identifying three distinct regimes governed by cooperativity, which quantifies the interplay between interaction strength and losses. Our findings establish a framework to detect strong coupling, unveiling resonance-dependent features in the emission spectrum and photon correlations.

Atomically precise graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic applications due to their widely tunable energy band gaps resulting from lateral quantum confinement and edge effects. Here we report on the electronic transport characterization of an edge-modified GNR suspended between the tip of a scanning tunneling microscope (STM) and a Au(111) substrate. Differential conductance measurements on this metal-GNR-metal junction reveal loss-less transport properties (inverse decay length β<0.001Å) with high conductance (0.1 G₀) at low voltages (50 meV) over long distances (z>10 nm). The transport behavior is sensitive to the coupling between ribbon and electrodes, an effect that is rationalized using tight-binding and density functional theory simulations. From extensive modelling we infer that the length-independent transport is a manifestation of band transport through topological valence states, which originate from the zigzag segments on the GNR edges.