Contents

JETP Letters

Vol. 123, No. 8, 2026

ASTROPHYSICS, SPACE PHYSICS, COSMOLOGY, AND GRAVITY

Thermodynamics of Kerr Black Hole: Tsallis–Cirto Composition Law and Entropy Quantization

G. E. Volovik p. 509  abstract

OPTICS AND LASER PHYSICS

“Two-Color” Difference Frequency Generation Due to Type-I and Type-II Phase Matching in a Nonlinear BaGa2GeS6 Crystal Pumped by Femtosecond Ti:Sapphire Laser Pulses

I. O. Kinyaevskiy, M. V. Ionin, A. V. Koribut, Ya. V. Grudtsyn, Yu. M. Klimachev, and D. V. Badikov p. 514  abstract

Correlations of the Phase Gradients of the Light Wave Propagating in a Turbulent Medium in the Regime of Weak Scintillations

V. A. Bogachev, I. V. Kolokolov, V. V. Lebedev, A. V. Nemtseva, and F. A. Starikov p. 521  abstract

OPTICS AND LASER PHYSICS

Photon Echo in Uniaxially Stressed Germanium with Antimony Donors

R. Kh. Zhukavin, V. D. Kukotenko, P. A. Bushuikin, Yu. Yu. Choporova, N. D. Osintseva, K. A. Kovalevsky, V. V. Tsyplenkov, V. V. Gerasimov, N. Dessmann, N. V. Abrosimov, and V. N. Shastin p. 529  abstract

OPTICS AND LASER PHYSICS

Raman Scattering and Spin–Phonon Coupling in Crystals of the Magnetic Topological Insulator MnBi2Te4

A. A. Maksimov, I. I. Tartakovskii, N. A. Abdullaev, Z. S. Aliev, and N. T. Mamedov p. 535  abstract

OPTICS AND LASER PHYSICS

Forward and Backward Lasing from an Ultraviolet Filament in Argon

G. E. Rizaev, M. V. Levus, T. A. Dick, and L. V. Seleznev p. 540  abstract

CONDENSED MATTER

Fluctuating Conductance of Mesoscopic Conductors Based on a Highly Disordered Two-Dimensional Semimetal in an HgTe Quantum Well

D. A. Kurmachev, Z. D. Kvon, and N. N. Mikhailov p. 544  abstract

CONDENSED MATTER

Synchrotron Small-Angle Scattering Study of Concentrated Ferrofluids Based on Strontium Hexaferrite Nanoparticles in a Magnetic Field

N. A. Grigoryeva, A. A. Eliseev, P. E. Kazin, A. A. Semina, A. P. Chumakov, A. A. Eliseev, and S. V. Grigoriev p. 548  abstract

Josephson Diode and Spin-Valve Effects on the Surface of Altermagnet CrSb

V. D. Esin, D. Yu. Kazmin, Yu. S. Barash, A. V. Timonina, N. N. Kolesnikov, and E. V. Deviatov p. 556  abstract

METHODS OF PHYSICAL RESEARCH

Geometric Phase of the Two-Particle Bethe Wavefunction

V. A. Tomilin, A. M. Rostom, and L. V. Il’ichev p. 566  abstract

QUANTUM INFORMATICS

Kitaev–Ising-J1-J2 Model: A Density Matrix Renormalization Group Study

A. V. Kapranov and R. S. Akzyanov p. 573  abstract