The OP has indicated the solution he is looking for, in terms of a device's unattainable ideal V-I characteristics.
If the OP would specify the problem or objective to which such a device might be a solution, we could provide more concrete help.
In most walks of life, technical or non-technical, if we know the reason for the question you will probably get a better answer. Either the answer will be more pertinent to your needs, or perhaps it can suggest a better alternative that you haven’t even considered. Don’t ask “Can you give me a lift into town?” Do ask “Can you give me a lift into town, so I can replace my broken frobnitz?”. The answer might be “There’s a spare frobnitz in the attic”, thus saving time, money, the environment – as well as making some space in the attic.