Is there a way to Marshal a byte[] into a string without copying in C#?

Question

I am in the process of building a sub-part of a native application, namely a Unity application that runs as a child of a different application written in a completely different language. Since we have to run on mobile devices and we need to share a lot of data between the two parts, we are looking into a way to pass pointers to strings from the wrapper application to the Unity child.

I have however run into a problem when it comes to marshalling, namely that Marshal.PtrToString(Ansi/Auto/Etc) all specify in the documentation that they will copy the content of the IntPtr to a new managed string, which defeats the point.

Our goal is to read the data as a string without creating another copy. It has to be seen as a string at compile time as a library we use only accepts strings as arguments.

Is there any way to do so? Unsafe code is acceptable.