Transition to the Haldane phase driven by electron-electron correlations.

One of the most famous quantum systems with topological properties, the spin [Formula: see text] antiferromagnetic Heisenberg chain, is well-known to display exotic [Formula: see text] edge states. However, this spin model has not been analyzed from the more general perspective of strongly correlated systems varying the electron-electron interaction strength. Here, we report the investigation of the emergence of the Haldane edge in a system of interacting electrons - the two-orbital Hubbard model-with increasing repulsion strength U and Hund interaction JH. We show that interactions not only form the magnetic moments but also form a topologically nontrivial fermionic many-body ground-state with zero-energy edge states. Specifically, upon increasing the strength of the Hubbard repulsion and Hund exchange, we identify a sharp transition point separating topologically trivial and nontrivial ground-states. Surprisingly, such a behaviour appears already at rather small values of the interaction, in a regime where the magnetic moments are barely developed.

Interaction-induced topological phase transition and Majorana edge states in low-dimensional orbital-selective Mott insulators.

Topological phases of matter are among the most intriguing research directions in Condensed Matter Physics. It is known that superconductivity induced on a topological insulator's surface can lead to exotic Majorana modes, the main ingredient of many proposed quantum computation schemes. In this context, the iron-based high critical temperature superconductors are a promising platform to host such an exotic phenomenon in real condensed-matter compounds. The Coulomb interaction is commonly believed to be vital for the magnetic and superconducting properties of these systems. This work bridges these two perspectives and shows that the Coulomb interaction can also drive a canonical superconductor with orbital degrees of freedom into the topological state. Namely, we show that above a critical value of the Hubbard interaction the system simultaneously develops spiral spin order, a highly unusual triplet amplitude in superconductivity, and, remarkably, Majorana fermions at the edges of the system.

Correspondence of cytological and histopathological diagnoses in diagnostic category V of the Bethesda system: "suspicious for malignancy".

The progress in imaging methods enables fine needle aspiration (FNA) biopsy to be performed on smaller and smaller lesions, including malignant ones (papillary microcarcinomas). The follicular variant predominates in this group, with cytological features often not permitting an unbiased interpretation. The aim of the study was to determine the degree of reliability of the "suspicious for malignancy" (SM) diagnosis in material from the Institute of Oncology in Gliwice (IO). 290 primary SM diagnoses were established from 2010 to 2015 in the IO, including the consultations. None of the patients was treated surgically after the first FNA resulting in diagnostic category V (DC V). After the second FNA 80 patients underwent surgery, after the third 58, and after subsequent FNA 10. Together, 148 surgical resections were performed. Among 148 patients treated surgically, 111 were diagnosed with malignant lesions, which constitutes 75%. Predominantly - in 91 cases - the histopathological outcome was papillary carcinoma. The others were: 16 medullary carcinomas, 2 follicular carcinomas, and 2 poorly differentiated carcinoma cases. Moreover, 8 follicular adenomas and 28 nonneoplastic lesions were found. The high positive predictive value (PPV = 75%) of SM diagnosis established in the IO testifies to the high reliability of this test. Diagnostic category V in FNA should be an indication for surgical treatment.