10 papers
Quasicrystalline oxide interfaces by twisting SrTiO3 membranes
Shivasheesh Varshney, Sooho Choo, Huan Liu +34
Quasicrystals reveal that long-range order can exist without translational periodicity, but deterministic routes for designing strongly bonded quasicrystalline interfaces remain un…
Light-Driven Ultrafast Control of Time-Reversal Symmetry in SrTiO3
In Hyeok Choi, Sergei Urazhdin, Shivasheesh Varshney +3
Light-driven control of material symmetry enables the engineering of phenomena forbidden in equilibrium. Although electromagnetic fields have been used to break time-reversal symme…
Wafer-scale High-k SrTiO3 Dielectrics with Rational Barrier-layer Design for Low Leakage and High Charge Density
Majid Mohseni, Shivasheesh Varshney, Seung Gyo Jeong +3
High-k oxides such as SrTiO3 promise large capacitance, but their dielectric response is often limited by leakage currents due to reduced bandgaps. We show that introducing a thin…
Hybrid MBE Route to Adsorption-Controlled Growth of BaTiO3 Membranes with Robust Polarization Switching
S. Choo, S. Varshney, J. Shah +5
Freestanding ferroelectric membranes are promising for flexible electronics, nonvolatile memory, photonics, and spintronics, but their synthesis is challenged by the need for repro…
Superconducting Dome in Ionic Liquid Gated Homoepitaxial Strontium Titanate Thin Films
Sushant Padhye, Jin Yue, Shivasheesh Varshney +3
In this work, we patterned a two-dimensional electron gas (2DEG) on the surface of a SrTiO thin film grown homoepitaxially on SrTiO by hybrid molecular beam epitaxy (hMBE).…
Interfacial strong coupling and negative dispersion of propagating polaritons in freestanding oxide membranes
Brayden Lukaskawcez, Shivasheesh Varshney, Sooho Choo +12
Membranes of complex oxides like perovskite SrTiO3 extend the multi-functional promise of oxide electronics into the nanoscale regime of two-dimensional materials. Here we demonstr…
Absence of two-phonon quasi-elastic scattering in the normal state of doped--SrTiO by THz pump-probe spectroscopy
K. Santhosh Kumar, David Barbalas, Rishi Bhandia +4
Multi-pulse nonlinear THz spectroscopies enable a new understanding of interacting metallic systems via their sensitivity to novel correlation functions. Here, we investigated the…
Epitaxially Grown Single-Crystalline SrTiO3 Membranes Using a Solution-Processed, Amorphous SrCa2Al2O6 Sacrificial Layer
Shivasheesh Varshney, Martí Ramis, Sooho Choo +2
Water-soluble sacrificial layers based on epitaxially-grown, single crystalline (Ca, Sr, Ba)3Al2O6 layer are widely used for creating free-standing perovskite oxide membranes. Howe…
Anomalous frequency and temperature dependent scattering in the dilute metallic phase in lightly doped-SrTiO
K. Santhosh Kumar, Dooyong Lee, Shivasheesh Varshney +2
The mechanism of superconductivity in materials with aborted ferroelectricity and the emergence of a dilute metallic phase in systems like doped-SrTiO are outstanding issues in…
Fast and Facile Synthesis Route to Epitaxial Oxide Membrane Using a Sacrificial Layer
Shivasheesh Varshney, Sooho Choo, Liam Thompson +7
The advancement in thin-film exfoliation for synthesizing oxide membranes has opened up new possibilities for creating artificially-assembled heterostructures with structurally and…