sLORETA: N100 Brain Activation Maxima.

<p>sLORETA: N100 Brain Activation Maxima.</p

Tunneling Plasmonics in Bilayer Graphene

We report experimental signatures of plasmonic effects due to electron tunneling between adjacent graphene layers. At subnanometer separation, such layers can form either a strongly coupled bilayer graphene with a Bernal stacking or a weakly coupled double-layer graphene with a random stacking order. Effects due to interlayer tunneling dominate in the former case but are negligible in the latter. We found through infrared nanoimaging that bilayer graphene supports plasmons with a higher degree of confinement compared to single- and double-layer graphene, a direct consequence of interlayer tunneling. Moreover, we were able to shut off plasmons in bilayer graphene through gating within a wide voltage range. Theoretical modeling indicates that such a plasmon-off region is directly linked to a gapped insulating state of bilayer graphene, yet another implication of interlayer tunneling. Our work uncovers essential plasmonic properties in bilayer graphene and suggests a possibility to achieve novel plasmonic functionalities in graphene few-layers

Linear Regression Analyses: Variables.

<p>Linear Regression Analyses: Variables.</p

N100 sLORETA Genotype Group Comparisons.

<p>N100 sLORETA Genotype Group Comparisons.</p

Pairwise correlation (r-squared) between the 6 SNPs on exon 5 of the CHRNA4 gene in our sample.

<p>The image was created using Haploview [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#pone.0152984.ref043" target="_blank">43</a>]. Genomic positions are given in hg19 coordinates.</p

Quartile-quartile boxplot with genotype rs1044396 effects on event-related potential N100 amplitude (standardized values at electrode position Cz) in the general population.

<p>a) <i>Top</i>: Genotype effects in the entire sample (males and females). <i>Bottom</i>: Genotype effects separately depicted for males and females. Stepwise linear regression analysis of the event-related potential N100 at vertex electrode position Cz, with age, gender, education, smoking status and study site as covariates and testing for up to 3-factor interactions among the predictors, revealed a significant genotype effect (for details see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#sec008" target="_blank">results</a> section). b) Functional neuroimaging sLORETA current density analyses of genotype groups with covariates age, gender, study site. <i>Top</i>: Current density for genotype groups (<i>P</i> < 0.01). <i>Bottom</i>: genotype group contrasts (t-values corrected for multiple testing). Independent of genotype, the strongest N100 activation maximum is seen in the left temporal lobe followed by a maximum in the frontal lobe mostly in the left hemisphere. This is consistent with intracortical recordings [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#pone.0152984.ref044" target="_blank">44</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#pone.0152984.ref046" target="_blank">46</a>] as well as earlier LORETA studies conducted by us [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#pone.0152984.ref021" target="_blank">21</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#pone.0152984.ref023" target="_blank">23</a>] using comparable task conditions. For details on genotype effects see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0152984#sec008" target="_blank">result</a> section.</p

Genotype Effects on Reaction Time.

<p>Genotype Effects on Reaction Time.</p

Event-related potentials (ERPs) incl.

<p>N100 during auditory oddball task (target responses) at electrode positions Fz and Cz for rs1044396 genotype groups. Note: response curves are uncorrected for covariates.</p

Genotype Effects on N100 Event-Related Potential (Cz).

<p>Genotype Effects on N100 Event-Related Potential (Cz).</p

Socio-demographic Data.

<p>Socio-demographic Data.</p