Launching Hyperbolic Phonon Polaritons with a rod antenna

Hi everyone,

I am trying to reproduce figures 4f and 4i from the open-access paper: " Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas" (link below). This paper uses metallic rod antennas to launch polaritons in hBN slab (which is an anisotropic 2D material that supports volume polaritons).
https://www.nature.com/articles/s41467-019-11143-7?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=3_nsn6445_deeplink_PID2190813&utm_content=deeplink

image

Although the results are close, my simulation shows some extra field normal to the antenna border (indicated in the figure). I have tried to change the mesh resolution, the source type from TFSF to a Gaussian beam, and even the PML boundaries from standard to stabilizes. All these attempts resulted in the same near-field profile.

It is worth saying that I would not expect this extra field since the experimental and simulated data from the paper does not present this artifact.

I would be greatly thanked if anyone could help me with this issue.

Best Regards,

Obs: I am using version 8.23 of FDTD solutions.
Antenna_on_hBN_fig_4.fsp (303.2 KB)

Hello @rafael.mayer,

I noticed that the paper says the fields are recorded at the top surface of the antenna, while your monitor is near the middle. Try moving the monitor to the top surface of the antenna and running it again, and let me know if that helps.

Hi @kjohnson,

Thank you for the answer. But, your statement is incorrect. The paper says “Simulated near-field distribution |Ez(x, y)| (taken 150 nm away from the h-BN slab)”.

Moreover, you were looking at the film monitor (located at the middle of the antenna), and not the frequency-power monitor, located 150 nm above the antenna surface (“z_plane”).

Please, let me know if there is any advance in this issue.

UPDATE:

The TFSF source is few mesh cells apart from the monitor. To fix this, I increased the mesh resolution in the z direction, but I still got the same field profile.

Dear fellows,

I found that when I simulate the antenna using p-polarized light with the E field along the antenna axis, I got the same answer as the paper. Thus, I’m closing this topic. Thank you for all who participated.

Hello @rafael.mayer,

I am glad to hear you found a solution! Thank you for letting us know.