Steady--State Current Signatures of Strong Light--Matter Coupling in Single--Molecule Junctions

Kritanjan Polley; Norah M. Hoffmann

Home/Archive/arXiv

arXiv · 2609.31265

Steady--State Current Signatures of Strong Light--Matter Coupling in Single--Molecule Junctions

Kritanjan Polley·Norah M. Hoffmann

View original source ↗Read source document ↗Export metadata ↓

Abstract

Strong light-matter coupling offers exciting opportunities for controlling molecular properties, yet resolving single-molecule behavior from collective effects remains a challenge. Recent experiments in scanning tunneling microscope break junctions (STM-BJs) have demonstrated strong light-matter coupling at the single-molecule level. Because STM-BJs provide direct access to molecular-junction currents, we investigate whether strong coupling leaves a measurable fingerprint in transport, potentially probing polaritonic states beyond optical spectroscopy. Using a semiclassical mapping approach for nonequilibrium quantum transport, we find that steady-state current indeed carries a direct signature of single-molecule strong coupling. We test the robustness of this signature against electrode connectivity, nuclear motion, spatially structured electromagnetic modes, and solvent effects. While environmental factors and nuclear motion reshape the signature, the current is not a passive response but is actively influenced by coupled molecular dynamics. Our work establishes current as a tool to interpret and control strong light-matter interactions in nanoscale junctions.

Explore related subjects

quant-ph cond-mat.mes-hall

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Kritanjan Polley, Norah M. Hoffmann. 2026-09-25. Steady--State Current Signatures of Strong Light--Matter Coupling in Single--Molecule Junctions. https://arxiv.org/abs/2609.31265

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Spectral moments and entropy rigidity of quantum channels: a three-mode photonic witness

Majorization and von Neumann entropy provide related but inequivalent descriptions of spectral disorder in quantum optical states. We investigate the channels preserving these descriptions and propose a three-mode photonic test of their difference. For channels with equal input and output dimensions, we show that constant output purity and third spectral moment on the unitary orbit of one simple-spectrum state determine the majorization-preserving channel forms, without assuming unitality.For qubits, output purity alone is sufficient. Preservation of entropy equality is substantially more restrictive: in dimension $d\geqslant3$, even a local condition near the maximally mixed state permits only replacement and unitary channels. Qubits admit an additional depolarizing family, but this exception disappears under extension by an idle auxiliary qubit. We construct exactly entropy-matched qutrit inputs whose output entropies split at cubic order under nontrivial depolarizing noise. A proposed single-photon implementation uses three optical modes, randomized Weyl transformations and population or spectral-moment measurements.Explicit expressions are also obtained for preparation mismatch,readout uncertainty and input-independent loss. The results connect quadratic and cubic spectral information with experimentally interpretable tests of quantum-channel structure.

quant-ph↗

arXiv2026

Spectral diffusion of phosphorus donors in silicon at high magnetic field

We study the central spin physics of a phosphorus donor electron in silicon interacting with a silicon-29 bath at high magnetic field (8.59 T). We find that the spectral diffusion time is shorter and exhibits a larger anisotropy with respect to crystal orientation in the magnetic field than in previous measurements at 0.35 T. The increased anisotropy suggests a modification of the hyperfine interactions at high field. The 1.2 THz cyclotron energy is a significant fraction of the 10.8 THz Rydberg energy of the bound donor, which can result in a non-trivial magnetic perturbation of the hydrogenic donor wavefunction. Low-power, above-bandgap optical excitation is seen to increase the spectral diffusion time, recovering the low-field spectral diffusion time at most crystal orientations. Understanding such perturbations to the spatial wavefunction of donor electron spins could be key to engineering their high-fidelity control.

quant-ph↗

arXiv2026

Many-Body Bound States in the Continuum

A bound state in the continuum (BIC) is a spatially localized energy eigenstate embedded in a continuous spectrum of extended eigenstates. While diverse types of single-particle BICs have been reported in the literature, whether such states can exist in genuinely many-body systems remains an open question. Here, we present numerical evidence and a perturbative analysis supporting the existence of many-body BICs in a one-dimensional Bose-Hubbard chain with an attractive impurity potential, a system previously known to host a BIC in the two-particle sector. Furthermore, we demonstrate that the Bethe-type construction of the known two-particle BIC breaks down already for three particles even for arbitrary finite superpositions of Bethe waves. The resulting BICs violate the eigenstate thermalization hypothesis for several local one- and two-body observables, leading to nonthermal dynamics from experimentally accessible initial states.

quant-ph↗