kapralova_zdanska_2025 ====================== P\. R\. Kaprálová\-Žďánská, "Coherent superposition mediating energy flow between fundamental and third\-harmonic modes", Phys\. Rev\. A 111, 043105 \(2025\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1103/PhysRevA\.111\.043105 `__ **Source kind:** theory **Recorded technique:** Non\-Hermitian Floquet theory of two bound S states coupled through the continuum\: a two\-by\-two effective Floquet Hamiltonian \(Eqs\. 21\-27\) with a formal two\-photon Rabi frequency from counter\-rotating terms and complex \(ionisation\) widths; checked against full\-dimensional complex\-scaled Floquet calculations of He \(exponentially tempered Gaussian basis ExTG5G, L\_max = 2, singly excited bound and continuum states, scaling angles theta = 0\.2\-0\.4\) for linear polarisation near 120\.3 nm and up to 7\.5 TW/cm^2, fitted three ways \(quasi\-energy splits, Sec\. III; resonant\-beat laser parameters, Sec\. IV B; diabatic quasi\-energy surfaces, Sec\. IV C\)\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- THE LIBRARY COPY is the author's manuscript \(ResearchGate\), not the version of record\: 99 PDF pages, pp\. 1\-67 the article and pp\. 68\-99 'Supplementary Material' I and II; no journal reference on it, and its title reads 'Coherent superposition mediating energy flow between the fundamental and the third harmonic mode' \(the published title is the citation's\)\. Pages are PDF pages\. Values may differ from the published version; not checked against it\. NOTHING TAKEN \(the maintainer, 2026\-10\-08, TC\-872\)\: the coefficients of Table I stay in these notes\. Table I \(p\. 51, tbl\_ebf0fb433ade, checked against the image; merged cells\), the effective Hamiltonian's parameters at I\_0 = 0 from the three fits \(no star\: Sec\. III; \*\: Sec\. IV C; \*\*\: Sec\. IV B\)\: \|mu\_0\| = 2\.03 a\.u\. \(2\.03\*, 2\.02\*\*\), d\|mu\_0\| /dI\_0 = 0\.9e\-3 a\.u\./\(TW cm^\-2\) \(\-1e\-3\*\); arg mu\_0 = 3e\-3 rad \(2e\-4\*\); gamma = 25\.5 microE\_h/\(TW cm^\-2\) \(25\.7\*, 25\.9\*\*\); delta\_omega = 58 \(61\*, 60\.9\*\*\) microE\_h/\(TW cm^\-2\); gamma\_1s2 = \-0\.2 \(0\) \(\-0\.3\* \(0\)\) and gamma\_1s2s = 25\.3 \(25\.4\*\) microE\_h/\(TW cm^\-2\)\. The text gives gamma\_1s2s = 25\.2 \+\- 0\.2 microE\_h/\(TW cm^\-2\) for the Sec\. IV C fit \(p\. 44\), against Table I's 25\.4\*; the negative gamma\_1s2 is 'clearly a numerical artifact', probably below 1 microE\_h/\(TW cm^\-2\) \(p\. 44\)\. CONVENTIONS\. The 2 x 2 Floquet Hamiltonian is \(hbar/2\) \[\[\-Delta, Omega\], \[Omega, Delta\]\] \(Eq\. 24\)\: the off\-diagonal is hbar Omega/2, with hbar Omega = kappa I\_0 \(Eq\. 27\), kappa = mu\_0 sqrt\(2/\(c eps\_0\)\) \(Eq\. 80; Omega = mu\_0 I\_0 sqrt\(2/\(c eps\_0\)\), Eq\. 81\)\. The diabatic quasi\-energies carry I\_0 \(delta\_omega \- i gamma/2\) \(Eqs\. 25\-26\) with bound\-state widths written E \- i Gamma/2 \(Eq\. 28\)\: gamma I\_0 is a full width, and the population of 1s2s decays at gamma\_1s2s I\_0/hbar \(Eq\. 109\: 'gamma I\_0/2 hbar determines the average ionization rate over the Rabi cycle', half the time in each state\)\. Appendix F \(p\. 61\) prints 'I\_0\[TW/cm^2\] = 2\.84937923 x 10^\-5 I\_0\[a\.u\.\]' and sqrt\(2/\(c eps\_0\)\) = 0\.428255165 a\.u\.; the paper uses the first as I\_0\[a\.u\.\] = 2\.84937923e\-5 x I\_0\[TW/cm^2\] \(an atomic unit of intensity of 3\.5095e16 W/cm^2, the intensity of a unit field E\_0 with I = \(1/2\) eps\_0 c E\_0^2\)\: with it Eq\. 110 reproduces the printed a = 0\.52 \(0\.515 from gamma = 25\.5 and mu\_0 = 2\.03; computed 2026\-10\-08\); read as printed it would not\. THE IMPLIED 1s2s PHOTOIONISATION CROSS SECTION \(computed 2026\-10\-08, not data\)\: Gamma = gamma\_1s2s I\_0/hbar = 25\.3e\-6 E\_h / hbar = 25\.3e\-6 / 2\.41888e\-17 s = 1\.0459e12 s^\-1 per TW/cm^2; the photon at 120\.3 nm is 10\.3063 eV, Phi = 1e12/\(10\.3063 x 1\.602177e\-19\) = 6\.0563e29 cm^\-2 s^\-1 per TW/cm^2; sigma = 1\.727e\-18 cm^2 = 1\.73 Mb \(1\.720 and 1\.734 for 25\.2 and 25\.4\)\. kumar\_2026's Gamma\_e gives 1\.691e\-18 cm^2 at 120\.27 nm\: this is 2\.1 % higher; gamma is not a half\-width \(no factor 2\)\. In kumar\_2026's units \(E\_0^2 in a\.u\., I\_0\[a\.u\.\] = E\_0^2\)\: gamma\_1s2s = 0\.8879 E\_0^2 against kumar\_2026's Gamma\_e = 0\.869215 E\_0^2, and the coupling Omega = 2\.03 x 0\.428255 E\_0^2 = 0\.8694 E\_0^2 \(0\.8651 for 2\.02\*\*\) against kumar\_2026's Omega\_ge^P = 0\.886278 E\_0^2 \(1\.9 % apart\); both papers put Omega/2 off the diagonal\. Each of Kumar's two coefficients is closer to the other paper's other one \(0\.869215 against 0\.8694, 0\.02 %; 0\.886278 against 0\.8879, 0\.2 %\)\: see the register\. OTHER CONTENT, NOT TAKEN\: the exceptional\-point and Rabi\-cycle analysis \(Secs\. II C\-E, V; a = 0\.52 \+\- 0\.01, phi = \-\(0\.345 \+\- 0\.01\) pi, cot\(phi/2\) = 1\.65 \+\- 0\.05, Eq\. 111, p\. 47\), third\-harmonic emission, and the femtosecond Rabi cycling of Fig\. 19 \(with 1s2 \-\> 1s2p and 1s4p one\-photon comparisons\), figures and model parameters only\. FURTHER TWO\-PHOTON DATA CITED\: none with values; the He basis sets and earlier strong\-field calculations are the author's \(Refs\. 47\-48\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- No datasets are recorded. Formulas -------- No formulas are recorded. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.