>I don't mind granting my professor a temporary license to evaluate my work

That's a weird thing to say, and I'm not sure you understand when a license is and is not needed.

If you write an essay and hand me a physical copy, I can then do whatever I want with that copy. I can read it, I can shred it, I can put it in a filing cabinet to gather dust for 20 years.[1] I can even give, sell, or lend it to a friend! I can do all this without needing any special license, because I own the copy you have given me.

What copyright prevents is me photocopying, scanning, or even laboriously hand copying it, and then passing those copies to other people. But while you own the IP, I own the physical copy.

With digital works, the rules are a little different -- if you e-mail me a PDF, sending it to someone else would count as creating a copy, and I'd need your license to do so. But the essential fact is I don't need a special license to hold on to a copy of it. And if you give me permission to send it to someone else, once they have it they can hang onto it as well.

[1] Universities will of course have policies on how faculty handle student work, but that's an orthogonal issue to that of copyright.

I'm sure you are familiar with non-disclosure agreements. Those, and many other, possibly implicit, agreements severely limit what you may do with your 'physical copy'. 'Owning' the copy in no way entitles you to do with it whatever you want. Even telling others you own the copy is something that is easy to forbid.

I was taking issue of the OPs use of the word "license." A license grants you additional rights you would not otherwise possess.

If I'm discussing what actions are, by default, allowed -- well, it isn't very useful to tag a clause onto every statement saying "Unless a legal contract/agreement prevents you from doing otherwise."

That's taken as understood, and only worth mentioning if it is a right or freedom you can't sign away.

Edit: note that I wrote this from my Euro-centric point of view. Here universities are heavily subsidied and Ph.D. students are employees of the university.

No such license is needed. With enrollment in an educational facility, you sign over all rights on required course work to said facility. It's not your work, as little as work you do as an employee is your work: your employer owns all rights.

That is true of work done in University research labs, but course work, where you are paying to be there, not so much. Especially in undergrad and masters programs where students are less likely to work for the university.

That's not true. In my jurisdiction it is not even possible for a juristic person (i.e. company) to own any copyright whatsoever. Only a physical person can be a copyright owner here. So I do own the copyright of everything I do for my employer and certainly for anything I ever wrote or otherwise created in school.

Then the employee must have granted the employer a complete and exclusive right to use the copyrighted produces. There is not other solution: otherwise you can extort your company by threatening to leave and revoke all their rights to use your work of the past years. Many types of companies are near impossible without exclusive rights to the fruit of their employees' labour.

This is why in for instance The Netherlands, in every contract, an employer will by default demand all the rights related to work you do in your spare time, if it is related to your profession. And this makes complete sense: in the past, there have been problems with people that loved their job, did some work in the evenings for purely job-related stuff, became disgruntled later and successfully sued to the company for infringement.

That's not actually a universal fact. It's not uncommon to have someone publish a work that was initially submitted as an assignment so and there are university's that don't claim the copywrite on the work.