Scientists / Open questions

Ramamoorthy Ramesh

Multiferroics; oxide electronics

19 questions

Completing the spatially resolved steady-state negative-capacitance program: bias-dependent local constitutive mapping, rigorous local thermodynamics, and controllable negative-permittivity landscapes in multidomain ferroelectric heterostructures
Quantitative remanent polarization, microscopic origin, and tunnel-junction performance limits of ~1 nm ferroelectric Hf0.5Zr0.5O2 films grown directly on silicon
Quantitative piezoresponse metrology, interfacial amorphous-layer reliability, and device integration of ferroelectric PZT and BaTiO3 nanoshell tubes
Mechanistic origin and predictive design of piezoelectricity in smectically ordered M13 bacteriophage films
Microscopic mechanism of polarization-controlled electron tunneling into ferroelectric surfaces under a biased conductive tip
Strain-driven morphotropic phase boundaries in single-composition perovskites: genericity, device-level viability, and the thermodynamic-kinetic limits of the two-phase region
Deterministic electric-field control of room-temperature polar skyrmion bubbles: motion, switching, stability, and harnessing of skyrmion-based negative capacitance
Electronic and magnetic reconstruction of the octahedral-tilt-suppressed interfacial layer in BiFeO3/La0.7Sr0.3MnO3 epitaxial heterostructures: determination of its metallic character, mechanism partition, and atomic-scale magnetic order
Origin, quantitative microscopic description, and control of electronic conduction at ferroelectric domain walls in BiFeO3
Achieving large magnetoresistance at low fields and room temperature in perovskite manganites: the unresolved processing and mechanism questions from the La-Ca-Mn-O colossal-magnetoresistance films
Open problems in realizing scalable energy-efficient magnetoelectric spin–orbit (MESO) logic: experimental demonstration of cascaded, ~100 mV, attojoule-class circuits
Quantitative mechanisms of electrode-dependent polarization fatigue, retention, and imprint in Pb(Zr,Ti)O3 thin-film ferroelectric capacitors on silicon
Microscopic origin and experimental validation of the decoupling between lattice tetragonality and ionic displacements (local polarization) in ultrathin epitaxial PbTiO3-based ferroelectric films
Practical room-temperature antiferromagnetic memory: efficient electrical writing, robust readout margin, and device reliability (open agenda of the FeRh antiferromagnetic memory resistor)
Microscopic mechanism and materials design rules for the ferroelectric domain-wall photovoltaic effect
Accessing the intrinsic polarization-switching time and switching kinetics of thin-film ferroelectric capacitors below circuit-limited timescales
Deterministic room-temperature magnetoelectric control of ferrimagnetism in (LuFeO3)m/(LuFe2O4)1 superlattices: microscopic mechanism, spin-charge ground state, and the roles of strain and oxygen stoichiometry
Robustness, generality, thickness scaling, and rigorous electrostatics of the mixed-ferroic HfO2–ZrO2 superlattice gate stack for advanced transistors
Raising the open-circuit voltage and ambient stability of all-inorganic CsSnI3 lead-free perovskite solar cells: suppressing tin-vacancy self-doping and Sn2+ oxidation beyond the SnF2 vacancy-modulation baseline

Back to open problems

Completing the spatially resolved steady-state negative-capacitance program: bias-dependent local constitutive mapping, rigorous local thermodynamics, and controllable negative-permittivity landscapes in multidomain ferroelectric heterostructures

Quantitative remanent polarization, microscopic origin, and tunnel-junction performance limits of ~1 nm ferroelectric Hf0.5Zr0.5O2 films grown directly on silicon

Quantitative piezoresponse metrology, interfacial amorphous-layer reliability, and device integration of ferroelectric PZT and BaTiO3 nanoshell tubes

Mechanistic origin and predictive design of piezoelectricity in smectically ordered M13 bacteriophage films

Microscopic mechanism of polarization-controlled electron tunneling into ferroelectric surfaces under a biased conductive tip

Strain-driven morphotropic phase boundaries in single-composition perovskites: genericity, device-level viability, and the thermodynamic-kinetic limits of the two-phase region

Deterministic electric-field control of room-temperature polar skyrmion bubbles: motion, switching, stability, and harnessing of skyrmion-based negative capacitance

Electronic and magnetic reconstruction of the octahedral-tilt-suppressed interfacial layer in BiFeO3/La0.7Sr0.3MnO3 epitaxial heterostructures: determination of its metallic character, mechanism partition, and atomic-scale magnetic order

Origin, quantitative microscopic description, and control of electronic conduction at ferroelectric domain walls in BiFeO3

Achieving large magnetoresistance at low fields and room temperature in perovskite manganites: the unresolved processing and mechanism questions from the La-Ca-Mn-O colossal-magnetoresistance films

Open problems in realizing scalable energy-efficient magnetoelectric spin–orbit (MESO) logic: experimental demonstration of cascaded, ~100 mV, attojoule-class circuits

Quantitative mechanisms of electrode-dependent polarization fatigue, retention, and imprint in Pb(Zr,Ti)O3 thin-film ferroelectric capacitors on silicon

Microscopic origin and experimental validation of the decoupling between lattice tetragonality and ionic displacements (local polarization) in ultrathin epitaxial PbTiO3-based ferroelectric films

Practical room-temperature antiferromagnetic memory: efficient electrical writing, robust readout margin, and device reliability (open agenda of the FeRh antiferromagnetic memory resistor)

Microscopic mechanism and materials design rules for the ferroelectric domain-wall photovoltaic effect

Accessing the intrinsic polarization-switching time and switching kinetics of thin-film ferroelectric capacitors below circuit-limited timescales

Deterministic room-temperature magnetoelectric control of ferrimagnetism in (LuFeO3)m/(LuFe2O4)1 superlattices: microscopic mechanism, spin-charge ground state, and the roles of strain and oxygen stoichiometry

Robustness, generality, thickness scaling, and rigorous electrostatics of the mixed-ferroic HfO2–ZrO2 superlattice gate stack for advanced transistors

Raising the open-circuit voltage and ambient stability of all-inorganic CsSnI3 lead-free perovskite solar cells: suppressing tin-vacancy self-doping and Sn2+ oxidation beyond the SnF2 vacancy-modulation baseline