Stemmer Research Group
Functional oxide thin films and advanced structural characterization techniques

Selected Recent Publications Sorted by Topic

Complex Oxide Heterostructures and Strong Electron Correlations

Strong Electron Correlations and Related Phenomena in Low-Dimensional Systems

Evidence of a topological Hall effect in Eu1-xSmxTiO3, K. Ahadi, L. Galletti, and S. Stemmer, Appl. Phys. Lett. 111, 172403 (2017). Reprint. arXiv

Response of the lattice across the filling-controlled Mott metal-insulator transition of a rare earth titanate, H. Kim, P. B. Marshall, K. Ahadi, T. E. Mates, E. Mikheev, and S. Stemmer, Phys. Rev. Lett. 119, 186803 (2017). Reprint. ArXiv.

Disorder versus two transport lifetimes in a strongly correlated electron liquid, P. B. Marshall, H. Kim, and S. Stemmer, Sci. Rep. 7, 10312 (2017). arXiv.

Novel metal-insulator transition at the SmTiO3/SrTiO3 interface, K. Ahadi, and S. Stemmer, Phys. Rev. Lett. 118, 236803 (2017). Reprint.

Dichotomy of the transport coefficients of correlated electron liquids in SrTiO3, T. A. Cain, E. Mikheev, C. A. Jackson, S. Stemmer, arXiv:1609.04149 [cond-mat.str-el]

Pseudogaps and Emergence of Coherence in Two-Dimensional Electron Liquids in SrTiO3, P. B. Marshall, E. Mikheev, S. Raghavan, and S. Stemmer, Phys. Rev. Lett. 117, 046402 (2016). Reprint.

Interface-driven ferromagnetism within the quantum wells of a rare earth titanate superlattice, R. F. Need, B. J. Isaac, B. J. Kirby, J. A. Borchers, S. Stemmer, and S. D. Wilson, Phys. Rev. Lett. 117, 037205 (2016).

Key role of lattice symmetry in the metal-insulator transition of NdNiO3 films, J. Y. Zhang, H. Kim, E. Mikheev, A. J. Hauser, and S. Stemmer, Sci. Rep. 6, 23652 (2016). ArXiv.

Carrier density independent scattering rate in SrTiO3-based electron liquids, E. Mikheev, S. Raghavan, J. Y. Zhang, P. B. Marshall, A. P. Kajdos, L. Balents, S. Stemmer, Sci. Rep. 6, 20865 (2016).

Tuning bad metal and non-Fermi liquid behavior in a Mott material: rare earth nickelate thin films, E. Mikheev, A. J. Hauser, B. Himmetoglu, N. E. Moreno, A. Janotti, C. G. Van de Walle, and S. Stemmer, Sci. Adv. 1, e1500797 (2015). ArXiv.

Separation of transport lifetimes in SrTiO3-based two-dimensional electron liquids, E. Mikheev, C. R. Freeze, B. J. Isaac, T. A. Cain, and S. Stemmer, Phys. Rev. B 91, 165125 (2015). Reprint.

Correlation between stoichiometry, strain, and metal-insulator transitions of NdNiO3 films, A. J. Hauser, E. Mikheev, N. E. Moreno, J. Hwang, J. Y. Zhang, and S. Stemmer, Appl. Phys. Lett. 106, 092104 (2015). Reprint

Gaps and Pseudogaps in Perovskite Rare Earth Nickelates, S. J. Allen, A. J. Hauser, E. Mikheev, J. Y. Zhang, N. E. Moreno, J. Son, D. G. Ouellette, J. Kally, A. Kozhanov, L. Balents, and S. Stemmer, APL Materials 3, 062503 (2015).

Quantum critical behavior in confined SrTiO3 quantum wells embedded in antiferromagnetic SmTiO3, C. A. Jackson, J. Y. Zhang, C. R. Freeze, and S. Stemmer, Nat. Commun. 5, 4258 (2014).

Correlation between metal-insulator transitions and structural distortions in high-electron-density SrTiO3 quantum wells, J. Y. Zhang, C. A. Jackson, R. Chen, S. Raghavan, P. Moetakef, L. Balents, and S. Stemmer, Phys. Rev. B 89, 075140 (2014). Reprint.

Quantum confinement in oxide quantum wells, S. Stemmer, and A. J. Millis, MRS Bulletin 38, 1032 (2013).

Interface-induced magnetism in perovskite quantum wells, C. A. Jackson and S. Stemmer, Phys. Rev. B 88, 180403(R) (2013). Reprint.

Temperature-dependence of the Hall coefficient of NdNiO3 thin films, A. J. Hauser, E. Mikheev, N. E. Moreno, T. A. Cain, J. Hwang, J. Y. Zhang, and S. Stemmer, Appl. Phys. Lett. 103, 182105 (2013).

Magnetism and local structure in low-dimensional Mott insulating GdTiO3, J. Y. Zhang, C. A. Jackson, S. Raghavan, J. Hwang, and S. Stemmer, Phys. Rev. B 88, 121104(R) (2013). Reprint.

Symmetry lowering in extreme-electron-density perovskite quantum wells, J. Y. Zhang, J. Hwang, S. Raghavan, and S. Stemmer, Phys. Rev. Lett. 110, 256401 (2013). Reprint.

PRLcover

Toward an artificial Mott insulator: Correlations in confined, high-density electron liquids in SrTiO3, P. Moetakef, C. A. Jackson, J. Hwang, L. Balents, S. J. Allen, and S. Stemmer, Phys. Rev. B 86, 201102(R) (2012). Reprint and cond-mat preprint.

Probing the metal-insulator transition of NdNiO3 by electrostatic doping, J. Son, B. Jalan, A. P. Kajdos, L. Balents, S. J. Allen, and S. Stemmer, Appl. Phys. Lett. 99, 192107 (2011). Reprint and Cond-Mat. preprint.

Conductivity enhancement of ultrathin LaNiO3 films in superlattices, J. Son, J. M. LeBeau, S. J. Allen, S. Stemmer, Appl. Phys. Lett. 97, 202109 (2010). reprint

Low-dimensional Mott material: transport in ultrathin epitaxial LaNiO3 films, J. Son, P. Moetakef, J. M. LeBeau, D. Ouellette, L. Balents, S. J. Allen and S. Stemmer, Appl. Phys. Lett. 96, 062114 (2010). UC Postprint

Oxide 2DEGs (and some 3DEGs)

Electric field effect near the metal-insulator transition of a two-dimensional electron system in SrTiO3, K. Ahadi, O. F. Shoron, P. B. Marshall, E. Mikheev, and S. Stemmer, Appl. Phys. Lett. 110, 062104 (2017). Reprint.

Probing the metal-insulator transition in BaTiO3 by electrostatic doping, S. Raghavan, J. Y. Zhang, O. F. Shoron, and S. Stemmer, Phys. Rev. Lett. 117, 037602 (2016). Reprint

Two-dimensional electron liquid at the (111) SmTiO3/SrTiO3 interface, S. Raghavan, J. Y. Zhang, and S. Stemmer, Appl. Phys. Lett. 106, 132104 (2015).

Limitations to the room temperature mobility of two- and three-dimensional electron liquids in SrTiO3, E. Mikheev, B. Himmetoglu, A. P. Kajdos, P. Moetakef, T. A. Cain, C. G. Van de Walle, and S. Stemmer, Appl. Phys. Lett. 106, 062102 (2015). Reprint.

Two-Dimensional Electron Gases at Complex Oxide Interfaces, S. Stemmer and S. J. Allen, Ann. Rev. Mater. Res. 44, 151-171 (2014). {Click on this link for a free reprint}

Intrinsic Mobility Limiting Mechanisms in Strontium Titanate, A. Verma, A. P. Kajdos, T. A. Cain, S. Stemmer, and D. Jena, Phys. Rev. Lett. 112, 216601 (2014).

Subband structure of two-dimensional electron gases in SrTiO3, S. Raghavan, S. J. Allen, and S. Stemmer, Appl. Phys. Lett. 103, 212103 (2013). Reprint.

Two-dimensional electron gas in a modulation-doped SrTiO3/Sr(Ti,Zr)O3 heterostructure, A. P. Kajdos, D. G. Ouellette, T. A. Cain, and S. Stemmer, Appl. Phys. Lett. 103, 082120 (2013). Reprint.

Conduction-band edge and Shubnikov–de Haas effect in low-electron-density SrTiO3, S. J. Allen, B. Jalan, S. B. Lee, D. G. Ouellette, G. Khalsa, J. Jaroszynski, S. Stemmer, and A. H. MacDonald, Phys. Rev. B 88, 045114 (2013).

Quantum oscillations from a two-dimensional electron gas at a Mott/band insulator interface, P. Moetakef, D. G. Ouellette, J. R. Williams, S. J. Allen, L. Balents, D. Goldhaber-Gordon, and S. Stemmer, Appl. Phys. Lett. 101, 151604 (2012). Reprint.

Modulation doping to control the high-density electron gas at a polar/non-polar oxide interface, T. A. Cain, P. Moetakef, C. A. Jackson, and S. Stemmer, Appl. Phys. Lett. 101, 111604 (2012). Reprint.

Carrier-controlled ferromagnetism in SrTiO3, Pouya Moetakef, James R. Williams, Daniel G. Ouellette, Adam P. Kajdos, David Goldhaber-Gordon, S. James Allen, and Susanne Stemmer, Physical Review X 2, 021014 (2012).
Featured "Editor's Choice" in Science.

Capacitance-voltage analysis of high-carrier-density SrTiO3/GdTiO3 heterostructures, Clayton A. Jackson, Pouya Moetakef, S. James Allen, and Susanne Stemmer, Appl. Phys. Lett. 100, 232106 (2012).

Electrostatic carrier doping of GdTiO3/SrTiO3 interfaces, P. Moetakef, T. A. Cain, D. G. Ouellette, J. Y. Zhang, D. O. Klenov, A. Janotti, C. G. Van de Walle, S. Rajan, S. J. Allen, and S. Stemmer, Appl. Phys. Lett. 99, 232116 (2011). Reprint

Enhancing the electron mobility of SrTiO3 with strain, B. Jalan, S. J. Allen, G. E. Beltz, P. Moetakef, S. Stemmer, Appl. Phys. Lett. 98, 132102 (2011). reprint

Transport in ferromagnetic GdTiO3/SrTiO3 heterostructures, P. Moetakef, J. Y. Zhang, A. Kozhanov, B. Jalan, R. Seshadri, S. J. Allen and S. Stemmer, Appl. Phys. Lett. 98, 112110 (2011). reprint

Two-dimensional electron gas in delta-doped SrTiO3, B. Jalan, S. Stemmer, S. Mack, S. J. Allen, Phys. Rev. B 82, 081103(R) (2010). reprint

Epitaxial SrTiO3 films with electron mobilities exceeding 30,000 cm2V-1s-1, J. Son, P. Moetakef, B. Jalan, O. Bierwagen, N. J. Wright, R. Engel-Herbert, S. Stemmer, Nature Mater. 9, 482 (2010).

High-mobility Perovskite Stannates

Structure and optical band gaps of (Ba,Sr)SnO3 films grown by molecular beam epitaxy, T. Schumann, S. Raghavan, K. Ahadi, H. Kim, and S. Stemmer, J. Vac. Sci. Technol. A 34, 050601 (2016). reprint

Conduction band edge effective mass of La-doped BaSnO3, S. J. Allen, S. Raghavan, T. Schumann, K.-M. Law, and S. Stemmer, Appl. Phys. Lett. 108, 252107 (2016). reprint

High-mobility BaSnO3 grown by oxide molecular beam epitaxy, S. Raghavan, T. Schumann, H. Kim, J. Y. Zhang, T. A. Cain, and S. Stemmer, APL Mater. 4, 016106 (2016).

Devices

BaTiO3/SrTiO3 heterostructures for ferroelectric field effect transistors, O. F. Shoron, S. Raghavan, C. R. Freeze, and S. Stemmer, Appl. Phys. Lett. 110, 232902 (2017).

Modulation of over 1014 cm-2 electrons in SrTiO3/GdTiO3 heterostructures, M. Boucherit, O. Shoron, C. A. Jackson, T. A. Cain, M. L. C. Buffon, C. Polchinski, S. Stemmer, and S. Rajan, Appl. Phys. Lett. 104, 182904 (2014).

Extreme charge density SrTiO3/GdTiO3 heterostructure field effect transistors, M. Boucherit, O. F. Shoron, T. A. Cain, C. Jackson, S. Stemmer, and S. Rajan, Appl. Phys. Lett. 102, 242909 (2013).

A heterojunction modulation-doped Mott transistor, J. Son, S. Rajan, S. Stemmer, and S. J. Allen, J. Appl. Phys. 110, 084503 (2011). Reprint and CondMat. preprint.

Electric Field Tunable Dielectric Films

Role of film stoichiometry and interface quality in the performance of (Ba,Sr)TiO3 tunable capacitors with high figures of merit, C. R. Freeze and S. Stemmer, Appl. Phys. Lett. 109, 192904 (2016). reprint

(Ba,Sr)TiO3 tunable capacitors with RF commutation quality factors exceeding 6000, C. J. G. Meyers, C. R. Freeze, S. Stemmer, and R. A. York, accepted, Appl. Phys. Lett. 109, 112902 (2016).

Electric field-tunable BaxSr1-xTiO3 films with high figures of merit grown by molecular beam epitaxy, E. Mikheev, A. P. Kajdos, A. J. Hauser, and S. Stemmer, Appl. Phys. Lett. 101, 252906 (2012). reprint

Resistive Switching

Tailoring resistive switching in Pt/SrTiO3 junctions by stoichiometry control, E. Mikheev, J. Hwang, A. P. Kajdos, A. J. Hauser, and S. Stemmer, Sci. Rep. 5, 11079 (2015).

Resistive switching and its suppression in Pt/Nb:SrTiO3 junctions, E. Mikheev, B. D. Hoskins, D. B. Strukov, and S. Stemmer, Nat. Commun. 5 3990 (2014).

Thermoelectric Properties

La-doped SrTiO3 films with large cryogenic thermoelectric power factors, Tyler A. Cain, Adam P. Kajdos, and Susanne Stemmer, Appl. Phys. Lett. 102, 182101 (2013). Reprint.

Seebeck coefficient of a quantum confined, high-electron-density electron gas in SrTiO3, Tyler A. Cain, SungBin Lee, Pouya Moetakef, Leon Balents, Susanne Stemmer, and S. James Allen, Appl. Phys. Lett. 100, 161601 (2012). Reprint.

Large Seebeck coefficients and thermoelectric power factor of La-doped SrTiO3 thin films, B. Jalan, S. Stemmer, Appl. Phys. Lett. 97, 042106 (2010). link to UC reprint

 

Scanning Transmission Electron Microscopy (mostly technique-related papers)

Direct observation of Sr vacancies in SrTiO3 by quantitative scanning transmission electron microscopy, H. Kim, J. Y. Zhang, S. Raghavan, and S. Stemmer, Phys. Rev. X 6, 041063 (2016).

Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling, J. Y. Zhang, J. Hwang, B. J. Isaac, and S. Stemmer, Sci. Rep 5, 12419 (2015).

Three-Dimensional Imaging of Individual Dopant Atoms in SrTiO3, J. Hwang, J. Y. Zhang, A. J. D'Alfonso, L. J. Allen, and S. Stemmer, Phys. Rev. Lett. 111, 266101 (2013). Reprint.

Structural origins of the properties of rare earth nickelate superlattices, J. Hwang, J. Son, J. Y. Zhang, A. Janotti, C. G. Van De Walle, and S. Stemmer, Phys. Rev. B 87, 060101(R) (2013). Reprint and cond-mat preprint.

Nanoscale quantification of octahedral tilts in perovskite films, J. Hwang, J. Y. Zhang, J. Son, and S. Stemmer, Appl. Phys. Lett. 100, 191909 (2012). Reprint and cond-mat preprint.

Determining ferroelectric polarity at the nanoscale, J. M. LeBeau, A. J. D'Alfonso, N. J. Wright, L. J. Allen, S. Stemmer, Applied Physics Letters 98, 052904 (2011). Reprint

Standardless Atom Counting in Scanning Transmission Electron Microscopy, J. M. LeBeau, S. D. Findlay, L. J. Allen, S. Stemmer, Nano Letters 10, 4405 (2010). Featured as "Editor's Choice" in Science.
If you or your institution do not have a subscription to Nano Letters, ACS has made available 50 free electronic reprints of this article. To download a reprint, follow this link.

Position averaged convergent beam electron diffraction: theory and applications, J. M. LeBeau, S. D. Findlay, L. J. Allen, S. Stemmer, Ultramicroscopy 110, 118 (2010).

Quantitative comparisons of contrast in experimental and simulated bright-field scanning transmission electron microscopy images, J. M. LeBeau, Adrian J. D'Alfonso, S. D. Findlay, S. Stemmer, L. J. Allen, Physical Review B 80, 174106 (2009). UC Postprint

High-angle scattering of fast electrons from crystals containing heavy elements: Simulation and experiment, J. M. LeBeau, S. D. Findlay, X. Wang, A. J. Jacobson, L. J. Allen, S. Stemmer, Phys. Rev. B 79, 214110 (2009).

Experimental quantification of annular dark-field images in scanning transmission electron microscopy, J. M. LeBeau, S. Stemmer, Ultramicroscopy 108, 1653 (2008).

Quantitative atomic resolution scanning transmission electron microscopy, J. M. LeBeau, S. D. Findlay, L. J. Allen, S. Stemmer, Physical Review Letters 100, 206101 (2008).

 

Dirac Semimetal Films

Negative magnetoresistance due to conductivity fluctuations in films of the topological semimetal Cd3As2, T. Schumann, M. Goyal, D. A. Kealhofer, and S. Stemmer, Phys. Rev. B 95, 241113(R) (2017). Reprint. ArXiv.

Molecular beam epitaxy of Cd3As2 on a III-V substrate, T. Schumann, M. Goyal, H. Kim, and S. Stemmer, APL Mater. 4, 126110 (2016).

 

Oxide Molecular Beam Epitaxy

Growth of strontium ruthenate films by hybrid molecular beam epitaxy, P. B. Marshall, H. Kim, K. Ahadi, and S. Stemmer, APL Mater. 5, 096101(2017). Arxiv.

Surface Reconstructions in Molecular Beam Epitaxy of SrTiO3, A. P. Kajdos, and S. Stemmer, Appl. Phys. Lett. 105, 191901 (2014). Reprint. Cond.mat.

Growth window and effect of substrate symmetry in hybrid molecular beam epitaxy of a Mott insulating rare earth titanate, P. Moetakef, J. Y. Zhang, S. Raghavan, A. P. Kajdos, and S. Stemmer, J. Vac. Sci. Technol. A 31, 041503 (2013).

Growth and properties of GdTiO3 films prepared by hybrid molecular beam epitaxy, P. Moetakef, D. G. Ouellette, J. Y. Zhang, T. A. Cain, S. J. Allen, S. Stemmer, J. Cryst. Growth 355, 166 (2012).

Suppression of vacancy defects in epitaxial La-doped SrTiO3 films, D.J. Keeble, B. Jalan, L. Ravelli, W. Egger, G. Kanda, and S. Stemmer, Appl. Phys. Lett. 99, 232905 (2011).

Analysis of carbon in SrTiO3 grown by hybrid molecular beam epitaxy, B. Jalan, J. Cagnon, T. E. Mates, S. Stemmer, J. Vac. Sci. Technol. A 27, 1365 (2009).

Stoichiometry optimization of homoepitaxial oxide thin films using x-ray diffraction, J. M. LeBeau, R. Engel-Herbert, B. Jalan, J. Cagnon, P. Moetakef, S. Stemmer, G. B. Stephenson, Appl. Phys. Lett. 95, 142905 (2009). UC Postprint

Microstructure of epitaxial rutile TiO2 films grown by molecular beam epitaxy on r-plane Al2O3, R. Engel-Herbert, B. Jalan, J. Cagnon, S. Stemmer, J. Cryst. Growth 312 149 (2009).

Molecular beam epitaxy of SrTiO3 with a growth window, B. Jalan, P. Moetakef, S. Stemmer, Appl. Phys. Lett. 95, 032906 (2009). UC Postprint

Growth of high-quality SrTiO3 films using a hybrid molecular beam epitaxy approach, B. Jalan, R. Engel-Herbert, N. J. Wright, S. Stemmer, J. Vac. Sci. Technol. A 27, 461 (2009).

 

High-k Dielectrics for III-V CMOS

Extremely scaled high-k/In0.53Ga0.47As gate stacks with low leakage and low interface trap densities, V. Chobpattana, E. Mikheev, J. Y. Zhang, T. E. Mates, and S. Stemmer, J. Appl. Phys. 116, 124104 (2014). Reprint.

Scaled ZrO2 dielectrics for In0.53Ga0.47As gate stacks with low interface trap densities, V. Chobpattana, T. E. Mates, J. Y. Zhang, and S. Stemmer, Appl. Phys. Lett. 104, 182912 (2014). Reprint.

Influence of plasma-based in-situ surface cleaning procedures on HfO2/In0.53Ga0.47As gate stack properties, V. Chobpattana, T. E. Mates, W. J. Mitchell, J. Y. Zhang, and S. Stemmer, J. Appl. Phys. 114, 154108 (2013). Reprint.

Nitrogen-passivated dielectric/InGaAs interfaces with sub-nm equivalent oxide thickness and low interface trap densities, V. Chobpattana, J. Son, J. J. M. Law, R. Engel-Herbert, Cheng-Ying Huang, and S. Stemmer, Appl. Phys. Lett. 102, 022907 (2013). Reprint.

Fixed charge in high-k/GaN metal-oxide-semiconductor capacitor structures, J. Son, V. Chobpattana, B. M. McSkimming, and S. Stemmer, Appl. Phys. Lett. 101, 102905 (2012).

Frequency dispersion in III-V metal-oxide-semiconductor capacitors, S. Stemmer, V. Chobpattana, and S. Rajan, Appl. Phys. Lett. 100, 233510 (2012). Reprint.

Influence of gate metallization processes on the electrical characteristics of high-k/In0.53Ga0.47As interfaces, G. J. Burek, Y. Hwang, A. D. Carter, V. Chobpattana, J. J. M. Law, W. J. Mitchell, B. Thibeault, S. Stemmer, M. J. W. Rodwell, J. Vac. Soc. B 29, 040603 (2011).

Influence of trimethylaluminum on the growth and properties of HfO2/In0.53Ga0.47As interfaces, Y. Hwang, R. Engel-Herbert, S. Stemmer, Appl. Phys. Lett. 98, 052911 (2011). reprint

Comparison of methods to quantify interface trap densities at dielectric/III-V semiconductor interfaces, R. Engel-Herbert, Y. Hwang, S. Stemmer, J. Appl. Physics 108, 124101 (2010). reprint

Quantification of trap densities at dielectric/III-V semiconductor interfaces, R. Engel-Herbert, Y. Hwang, S. Stemmer, Appl. Phys. Lett. 97, 062905 (2010). reprint

Effect of post-deposition anneals on the Fermi level response of HfO2/In0.53Ga0.47As gate stacks, Y. Hwang, R. Engel-Herbert, N. G. Rudawski, S. Stemmer, J. Appl. Phys. 108, 034111 (2010). reprint

Analysis of trap state densities at HfO2/In0.53Ga0.47As interfaces, Y. Hwang, R. Engel-Herbert, N. G. Rudawski, S. Stemmer, Appl. Phys. Lett. 96, 102910 (2010).

Chemical beam deposition of high-k gate dielectrics on III-V semiconductors: TiO2 on In0.53Ga0.47As, R. Engel-Herbert, Y. Hwang, J. M. LeBeau, Y. Zheng, S. Stemmer, in CMOS Gate-Stack Scaling - Materials, Interfaces and Reliability Implications, Mater. Res. Soc. Symp. Proc. Volume 1155, paper 1155-C13-02 (2009).