N. Peter Armitage

N. Peter Armitage

Associate Professor

Bloomberg 309
410-516-0621
npa@jhu.edu
Curriculum Vitae
Group/Lab Website
Google Scholar Profile

Biography
Teaching
Publications

N. Peter Armitage has been on the faculty of the Department of Physics and Astronomy at Johns Hopkins University since 2006. He is a physicist whose research centers on exotic electronic states of matter at low temperatures, including novel superconductors, exotic magnetic states, electronic glasses, topological insulators, strong spin-orbit coupling, and materials in proximity to quantum critical points. Like waves on the sea, the behavior of such systems is intrinsically collective and is not easily reduced to the properties of individual particles – i.e., they are emergent. Dr. Armitage's principal scientific interest is understanding how is it that large ensembles of strongly interacting, but fundamentally simple particles like electrons in solids act collectively to exhibit complex emergent quantum phenomena. He is exploiting (and developing) recent technical breakthroughs using very low frequency microwave and THz range radiation to probe these systems at their natural frequency scales. The material systems of interest require new measurement techniques as their relevant frequencies typically fall between the range of usual optical and electronic methods. He has been the recipient of a DARPA Young Faculty Award, an NSF Career Award, a Sloan Research Fellowship, was a three time Kavli Frontiers Fellow, the winner of the first William Spicer Award from SSRL in 2004, and was the winner of the 2005 William L. McMillan Award from the University of Illinois for "outstanding contributions in condensed matter physics."

  • Advance Condensed Matter Physics - Spring 2012
  • Classical Mechanics 105 - Fall 2011
  • Introduction to Condensed Matter Physics - Fall 2010
  • Introduction to Condensed Matter Physics - Fall 2009
  • Introduction to Condensed Matter Physics - Fall 2008
  • The Advanced and Intermediate Lab - Spring 2008

Please also check out my perpetually updated lecture notes on "Electrodynamics of correlated electron systems".

These are based on lectures I first gave at the "2008 Boulder School for Condensed Matter and Materials Physics."

See the videos of these lectures here: Formalism and Techniques and Examples and Advanced Analysis

Displaying the 20 most recent publications. View the Google Scholar Profile for complete publications list.

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NJ Laurita, GG Marcus, BA Trump, J Kindervater, MB Stone, TM McQueen, ...
Low energy magnon dynamics and magneto-optics of the skyrmionic Mott insulator Cu $ _2 $ OSeO $ _3$
arXiv preprint arXiv:1704.04228, 2017

RM Ireland, L Wu, M Salehi, S Oh, NP Armitage, HE Katz
Nonvolatile Solid-State Charged-Polymer Gating of Topological Insulators into the Topological Insulating Regime
arXiv preprint arXiv:1704.01021, 2017

D Chaudhuri, B Cheng, A Yaresko, QD Gibson, RJ Cava, NP Armitage
An optical investigation of the strong spin-orbital coupled magnetic semimetal YbMnBi $ _2$
arXiv preprint arXiv:1701.08693, 2017

L Wu, M Salehi, N Koirala, J Moon, S Oh, NP Armitage
Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator
Science 354 (6316), 1124-1127, 2016

B Cheng, L Wu, SK Kushwaha, RJ Cava, NP Armitage
Measurement of the topological surface state optical conductance in bulk-insulating Sn-doped Bi 1.1 Sb 0.9 Te 2 S single crystals
Physical Review B 94 (20), 201117, 2016

L Zhao, CA Belvin, R Liang, DA Bonn, WN Hardy, NP Armitage, D Hsieh
A global inversion-symmetry-broken phase inside the pseudogap region of YBa2Cu3Oy
Nature Physics, 2016

NJ Laurita, CM Morris, SM Koohpayeh, PFS Rosa, WA Phelan, Z Fisk, ...
Anomalous three-dimensional bulk ac conduction within the Kondo gap of SmB 6 single crystals
Physical Review B 94 (16), 165154, 2016

M Brahlek, N Koirala, M Salehi, J Moon, W Zhang, H Li, X Zhou, MG Han, ...
Disorder-driven topological phase transition in B i 2 S e 3 films
Physical Review B 94 (16), 165104, 2016

A Akrap, M Hakl, S Tchoumakov, I Crassee, J Kuba, MO Goerbig, ...
Magneto-Optical Signature of Massless Kane Electrons in Cd 3 As 2
Physical Review Letters 117 (13), 136401, 2016

NJ Laurita, B Cheng, R Barkhouser, VA Neumann, NP Armitage
A Modified 8f Geometry with Reduced Optical Aberrations for Improved Time Domain Terahertz Spectroscopy
Journal of Infrared, Millimeter, and Terahertz Waves 37 (9), 894-902, 2016

NP Armitage
Quantum materials: Kitaev's exact solution approximated
Nature Materials 15 (7), 701-702, 2016

L Wu, RM Ireland, M Salehi, B Cheng, N Koirala, S Oh, HE Katz, ...
Tuning and stabilizing topological insulator Bi2Se3 in the intrinsic regime by charge extraction with organic overlayers
Applied Physics Letters 108 (22), 221603, 2016

B Cheng, L Wu, NJ Laurita, H Singh, M Chand, P Raychaudhuri, ...
Anomalous gap-edge dissipation in disordered superconductors on the brink of localization
Physical Review B 93 (18), 180511, 2016

M Neshat, NP Armitage, , NP Armitage
Terahertz time-domain spectroscopic ellipsometry system
US Patent 9,322,712, 2016

G Bossé, LD Pan, YS Li, LH Greene, J Eckstein, NP Armitage
Anomalous frequency and temperature-dependent scattering and Hund's coupling in the almost quantum critical heavy-fermion system CeFe 2 Ge 2
Physical Review B 93 (8), 085104, 2016

LD Pan, NJ Laurita, KA Ross, BD Gaulin, NP Armitage
A measure of monopole inertia in the quantum spin ice Yb2Ti2O7
Nature Physics, 2015

N Koirala, M Brahlek, M Salehi, L Wu, J Dai, J Waugh, T Nummy, MG Han, ...
Record surface state mobility and quantum hall effect in topological insulator thin films via interface engineering
arXiv preprint arXiv:1511.08939, 2015

L Wu, WK Tse, M Brahlek, CM Morris, RV Aguilar, N Koirala, S Oh, ...
High-resolution Faraday rotation and electron-phonon coupling in surface states of the bulk-insulating topological insulator Cu 0.02 Bi 2 Se 3
Physical review letters 115 (21), 217602, 2015

M Salehi, M Brahlek, N Koirala, J Moon, L Wu, NP Armitage, S Oh
Stability of low-carrier-density topological-insulator Bi2Se3 thin films and effect of capping layers
APL Materials 3 (9), 091101, 2015

VA Neumann, NJ Laurita, LD Pan, NP Armitage
Reduction of effective terahertz focal spot size by means of nested concentric parabolic reflectors
AIP advances 5 (9), 097203, 2015