This raises the intriguing thought that it might again be possible, in a manner similar to that used for PCM "pore" structures , to use existing published results from PCM link structures to predict the performance of the new structure at lithographic dimensions not yet obtainable.
Figure 2 shows the curves of the current density as a function of width  for link device structures. These curves indicate that the increases in reset current density are strongly dependent on the heat loss from the edges of the link. As the links are made very wide in relation to the thickness, the current density tends towards a constant value. The dissipated energy (J2/σ) is lost mostly from the upper and lower surfaces of the link.
Figure 2: Curves of current density for PCM "link" structures with those for WAL-PCM superimposed.
In the new WAL-PCM structure, the edges are folded into each other as illustrated in Figure 1, and are in effect removed, as is the heat loss associated with them. In a sense, from the thermal viewpoint, the link has become infinitely wide.
This means that it should be possible to describe the reset current density characteristics of the new WAL-PCM structures for any given value of GST thickness (t) and aperture diameter (d), as straight lines of constant current density, providing that the ratio d/t is large. In Figure 1, two examples of these proposed constant current characteristics have been added to the original (the green and orange lines) for film thickness of 3nm and 5nm respectively. These lines are asymptotic to the curve of the conventional link at very large values of width (w).
As stated earlier, the WAL-PCM device is considered a very wide link, irrespective of diameter as long as (d/t) is large. In Figure 1, it should be noted that the variable on the lower axis for the new WAL-PCM structure curves is the width of the equivalent conventional link length, calculated from the diameter.