condensed-matter

My Bachelor thesis is all around Excitons (specifially transitions between excitons of different energies). During my work I often had trouble with the spin and the wavefunction of them. Is there maybe some good (free) literature about the theory of excitons ? I found some books in the internet but they werent for free. And my university hasnone. 1) I read about "heavy holes" that can have spin o…

A University of Iowa research team has identified a less expensive method to calibrate magnetometers, devices that measure

I am reading Coleman's "Introduction to many-body physics" and am working on problem 4.2, which involves calculating the spectrum of the transverse-field Ising model. We start with the Hamiltonian $$ H = -J \sum_{j} S^{x}_{j} S^{x}_{j+1} -h \sum_{j} S^{z}_{j}. $$ I have successfully used a Jordan-Wigner transformation to turn it into fermion creation/annihilation operators as $$ H = \sum_j \lef…

QPHORIA is an annual meeting that brings researchers from the greater Pennsylvania and Ohio regions who focus on condensed matter physics, quantum information science and AMO physics. The meeting is designed for researchers to showcase their work. The event will take place Thursday, Oct. 1, and Friday, Oct. 2, in the Eric J. Barron Innovation Hub, Room 603, on Penn State's University Park campus.…

Scientists watched a light-triggered hidden state form inside a material in only 30 femtoseconds, revealing a step that had never been seen before. The material first entered a fleeting electronic state in which its bonds reorganized in a repeating pattern, followed by tiny atomic shifts. This ultrafast pathway could offer a new way to control electronic properties with light and help inspire fas…

Nature Communications, Published online: 21 August 2026; doi:10.1038/s41467-026-76908-3 Here, the authors show that erratic non-Hermitian skin localization allows acoustic waves to localize at disorder-dependent bulk positions while retaining ballistic transport, linking this behavior to the extreme-value statistics of random walks.

I'm trying to understand superfluidity from these Caltech notes on Advanced Statistical Physics (Week 1, Section IV: Landau Criterion for Superfluidity) - So far it is not clear why a moving superfluid doesn’t dissipate its kinetic energy. The spectrum of excitations is not gapped (which would be a sufficient condition for superflow), even though the number of low lying excitations is decreased r…

When a current flows through a junction or a contact between two metals of different conductivities a charge is accumulated in the vicinity of contact. The charge accumulated, I've read, is directly proportional to the current. In case current flows from a metal of large conductivity to a metal of small conductivity, charge accumulation is of positive type. Why so? And if there is such an accumul…

Electronic fluctuations can act as a resonant bridge between normally separate crystal vibrations, offering a new route to study and control ferroaxial quantum states. Symmetry is a basic rule of the natural world. It explains why some objects appear the same after they are rotated, reflected, or changed in other ways. In materials, symmetry helps [...]

Nature Electronics, Published online: 20 August 2026; doi:10.1038/s41928-026-01686-1 A multi-tone excitation technique can be used to generate octave-spanning magnonic frequency combs with thousands of lines in continuous yttrium iron garnet thin films.

When different materials transition from one phase to another, such as water coming to a boil or a magnet losing its ability to attract metals, something remarkable can happen: They begin to behave identically, following the same mathematical rules. “Physicists call this trait universality—the messy, microscopic details wash out and only a few essential features […]

Extreme experiments have revealed how diamond behaves at crushing pressures beyond those inside Neptune and Uranus, resolving a decades-old conflict between theory and observation. The results could help scientists boost fusion energy output while revealing more about the exotic diamond rain hidden inside ice giant planets.

Nature Communications, Published online: 20 August 2026; doi:10.1038/s41467-026-77007-z Various material systems exhibit coupling between distinct classes of polaritons. Here, the authors demonstrate anisotropic strong coupling between hyperbolic volume polaritons and isotropic surface polaritons in α-MoO3/AlN heterostructures.

MIT physicists found that two electronic phases inside the same quantum material emerge through surprisingly different mechanisms—one smoothly and the other in expanding pockets resembling growing ice crystals. The discovery could help explain how exotic properties such as superconductivity and magnetism develop and coexist.

The analysis estimates the critical bond dimension for the honeycomb lattice to be 2.634929344884, and the associated single-bond duality relation yields the triangular-lattice estimate 1.475661534848. This calculation uses star-triangle duality with symmetric-group permutation models on triangular and honeycomb lattices.

To model the inside of a supercapacitor, my team had to rework a common physics law that most high school students learn.

Don’t worry, understanding the work is a piece of cake. But it may make you hungry.

Forget solid, liquid, gas. This research used advanced math to theorize about topological phases of matter. And over the years experiments with matter and cold atoms have been validating the ideas.