The figure shows a series of resistance versus Temperature plots for Bismuth films of varying thickness. The red are thin, starting at 4 Angstroms, leading to the thickest violet film at 70 Angstroms.
An Angstrom is one tenth of a nanometer (0.1 nm). For purposes of comparison, a human hair is around 50,000 nm in diameter, the scratch resistant coating on your glasses may be in the 1000 nm range of thickness, and typical atomic spacing in a crystal is around 0.4 nm.
The phenomenon that the graph illustrates is that as the film grows in size, it changes from a normal-resistance to insulator transition (curve rising up steeply) to a normal-resistance to superconductor transition (resistance drops to zero at a Critical Temperature).
This transition of transitions is itself a critical phenomena, and Nina's PhD thesis will focus on what happens right around that pale green line where the transition occurs.
All pretty neat stuff.
Lastly, you're probably thinking curves like this could use some units. Right you are. I invite you to take a look at the same graph with labeled axes. The image is large however.
Those units take up some room.