Publications
Wrapping of Microparticles by Floppy Lipid Vesicles
Role of correlations in determining the Van Hove strain in Sr2 RuO4
Uniaxial pressure applied along a Ru-O-Ru bond direction induces an elliptical distortion of the largest Fermi surface of Sr2RuO4, eventually causing a Fermi surface topological transition, also known as a Lifshitz transition, into an open Fermi surface. There are various anomalies in low-temperature properties associated with this transition, including maxima in the superconducting critical temperature and in resistivity.
Imaging uncompensated moments and exchange-biased emergent ferromagnetism in FeRh thin films
Uncompensated moments (UMs) in antiferromagnets are responsible for exchange bias in antiferromagnet/ ferromagnet heterostructures; however, they are difficult to directly detect because any signal they contribute is typically overwhelmed by the ferromagnetic layer. We use magnetothermal microscopy to image micron-scale uncompensated moments in thin films of FeRh, a room-temperature antiferromagnet that exhibits a first-order phase transition to a ferromagnetic (FM) state near 400 K.
Fractionalized pair density wave in the pseudogap phase of cuprate superconductors
The mysterious pseudogap (PG) phase of cuprate superconductors has been the subject of intense investigation over the last 30 years, but without a clear agreement about its origin. Owing to a recent observation in Raman spectroscopy, of a precursor in the charge channel, on top of the well known fact of a precursor in the superconducting channel, we present here a novel idea: The PG is formed through a Higgs mechanism, where two kinds of preformed pairs, in the particle-particle and particle-hole channels, become entangled through a freezing of their global phase.
Magnetic handshake materials as a scale-invariant platform for programmed self-assembly
Programmable self-assembly of smart, digital, and structurally complex materials from simple components at size scales from the macro to the nano remains a long-standing goal of material science. Here, we introduce a platform based on magnetic encoding of information to drive programmable self-assembly that works across length scales. Our building blocks consist of panels with different patterns of magnetic dipoles that are capable of specific binding.
A New method for computing particle collisions in Navier-Stokes flows
Particle collisions in fluids are ubiquitous, but to compute the collision dynamics in a Navier-Stokes flow remains challenging. In addition to capturing the two-way coupling between the fluid and the particles, a key difficulty is to resolve the collision dynamics mediated by the flow. The gap between particles during collision is minuscule. This introduces a small length scale which needs to be resolved simultaneously with the flow at the large scale.
Dirac fermions and possible weak antilocalization in LaCuSb2
Layered heavy-metal square-lattice compounds have recently emerged as potential Dirac fermion materials due to bonding within those sublattices. We report quantum transport and spectroscopic data on the layered Sb square-lattice material LaCuSb2. Linearly dispersing band crossings, necessary to generate Dirac fermions, are experimentally observed in the electronic band structure observed using angle-resolved photoemission spectroscopy, along with a quasi-two-dimensional Fermi surface.
Materials Relevant to Realizing a Field-Effect Transistor Based on Spin–Orbit Torques
Spin-orbit torque (SOT) is a promising mechanism for writing magnetic memories, while field-effect transistors (FETs) are the gold-standard device for logic operation. The spin-orbit torque field-effect transistor (SOTFET) is a proposed device that couples an SOT-controlled ferromagnet to a semiconducting transistor channel via the transduction in a magnetoelectric multiferroic (MF). This allows the SOTFET to operate as both a memory and a logic device, but its realization depends on the choice of appropriate materials.
Modeling and Circuit Design of Associative Memories With Spin–Orbit Torque FETs
This article introduces a circuits model for a proposed spin-based device called a spin-orbit torque field-effect transistor (SOTFET) that can operate as a nonvolatile memory and logic device. The SOTFET utilizes an FET structure with a ferromagnetic-multiferroic (MF) gate-stack that enables read/compute and write functions to be isolated. This is achieved by a combination of a ferromagnetic layer that is programmable via spin-orbit torque coupled to an MF layer that also couples into the gate of a traditional FET.
Pressure-controlled interlayer magnetism in atomically thin CrI3
Stacking order can influence the physical properties of two-dimensional van der Waals materials1,2. Here we applied hydrostatic pressure up to 2 GPa to modify the stacking order in the van der Waals magnetic insulator CrI3. We observed an irreversible interlayer antiferromagnetic-to-ferromagnetic transition in atomically thin CrI3 by magnetic circular dichroism and electron tunnelling measurements. The effect was accompanied by a monoclinic-to-rhombohedral stacking-order change characterized by polarized Raman spectroscopy.