arXiv subjects

Aamir A. Makki

Publications and source records attributed to Aamir A. Makki.

3 recordsLinked to original sources

arXiv2026

Universality of long-wavelength behavior of composite-fermion Fermi liquid

A recent article evaluated the long-wavelength behavior of the projected static structure factor of the composite-fermion (CF) liquid within the zeroth-order microscopic theory and found $\bar{S}(\mathbf{q})\sim q^3$, in disagreement with the $\bar{S}(\mathbf{q})\sim q^3\ln q$ behavior predicted by the Chern-Simons field theory for the Coulomb interaction. Here we consider the possibility that the discrepancy arises because the zeroth-order CF Fermi-liquid wave function used in that work does not properly capture the long wavelength behavior. We use CF diagonalization to significantly improve the wave function but do not find any evidence for $\bar{S}(\mathbf{q})\sim q^3 \ln q$ behavior. Additionally, we find that the small-$q$ behavior of $\bar{S}(\mathbf{q})$ is also insensitive to the form of the interaction between electrons, suggesting universality.

cond-mat.str-el↗

arXiv2025

Probing fractional quantum Hall effect by photoluminescence

The recent discovery of fractional quantum anomalous Hall (FQAH) states - fractional quantum Hall (FQH) states realized without an external magnetic field - in twisted transition-metal dichalcogenide (TMD) bilayers represents a significant development in condensed matter physics. Notably, these states were first observed via photoluminescence (PL) spectroscopy. Surprisingly, a general theoretical understanding of PL is not available even for the standard FQH states. For an ideal two-dimensional system, the energy of the emitted photon is predicted to be independent of the correlations, but we show that the PL intensity contains valuable information. Specifically, we predict that at finite temperatures, the PL intensity peaks at the Jain fillings ν= n/(2n \pm 1), and away from these fillings, the binding energies of the composite-fermion excitons and trions can be deduced from the temperature dependence of the intensity. We discuss implications for PL experiments in semiconductor quantum wells and twisted TMD bilayers.

cond-mat.str-el↗

arXiv2025

Observation of tunable discrete time crystalline phases

Discrete time crystals (DTCs) are emergent non-equilibrium phases of periodically driven many-body systems, with potential applications ranging from quantum computing to sensing and metrology. There has been significant recent interest in understanding mechanisms leading to DTC formation and a search for novel DTC phases beyond subharmonic entrainment. Here, we report observation of multiple DTC phases in a nanoelectromechanical system (NEMS) based on coupled graphene and silicon nitride membranes. We confirm the time-crystalline nature of these symmetry broken phases by establishing their many-body characters, long-range time and spatial order, and rigidity against parameter fluctuation or noise. Furthermore, we employ controlled mechanical strain to drive the transitions between phases with different symmetries, thereby mapping the emergent time-crystalline phase diagram. Overall, our work takes a step towards establishing time crystals as a system with complexity rivaling that of solid state crystals.

cond-mat.mes-hall↗