@article{Yadav2019468,
  keywords = {Simulation, Steady state, Polarization, Electric field, Chemical structure, Electrical parameters, Priority journal, Electric capacitance, Letter, Scanning transmission electron microscopy, X-ray Diffraction, Energy density, Ferroelectric dielectric heterostructure, Negative capacitance},
  author = {A.K Yadav and K.X Nguyen and Z Hong and P Garc{\'\i}a-Fern{\'a}ndez and P Aguado-Puente and C.T Nelson and S Das and B Prasad and D Kwon and S Cheema and A.I Khan and C Hu and J {\'I}{\~n}iguez and J Junquera and L.-Q Chen and D.A Muller and Ramamoorthy Ramesh and S Salahuddin},
  title = {Spatially resolved steady-state negative capacitance},
  abstract = {Negative capacitance is a newly discovered state of ferroelectric materials that holds promise for electronics applications by exploiting a region of thermodynamic space that is normally not accessible1{\textendash}14. Although existing reports of negative capacitance substantiate the importance of this phenomenon, they have focused on its macroscale manifestation. These manifestations demonstrate possible uses of steady-state negative capacitance{\textemdash}for example, enhancing the capacitance of a ferroelectric{\textendash}dielectric heterostructure4,7,14 or improving the subthreshold swing of a transistor8{\textendash}12. Yet they constitute only indirect measurements of the local state of negative capacitance in which the ferroelectric resides. Spatial mapping of this phenomenon would help its understanding at a microscopic scale and also help to achieve optimal design of devices with potential technological applications. Here we demonstrate a direct measurement of steady-state negative capacitance in a ferroelectric{\textendash}dielectric heterostructure. We use electron microscopy complemented by phase-field and first-principles-based~(second-principles) simulations in SrTiO3/PbTiO3 superlattices to directly determine, with atomic resolution, the local regions in the ferroelectric material where a state of negative capacitance is stabilized. Simultaneous vector mapping of atomic displacements (related to a complex pattern in the polarization field), in conjunction with reconstruction of the local electric field, identify the negative~capacitance regions as those with higher energy density and larger polarizability: the domain walls where the polarization is suppressed. {\textcopyright} 2019, Springer Nature Limited.},
  year = {2019},
  booktitle = {Nature},
  journal = {Nature},
  series = {Nature},
  volume = {565},
  number = {7740},
  pages = {468-471},
  institution = {Nature Publishing Group},
  publisher = {Nature Publishing Group},
  issn = {00280836},
  doi = {10.1038/s41586-018-0855-y},
  note = {cited By 35},
  language = {eng},
}