Hey, it's that paper that's always referenced on the standard Eric Davis presentation on wormholes! I don't trust that guy too much because he writes a lot about aliens and psychic powers, but anyway.
Quantum effects, as well as some classical effects routinely violate almost every energy conditions that you can throw at them. So far quantum effects have been show to be able to break the trace energy condition, the strong energy condition, the weak energy condition, the null energy condition, the dominant energy condition, the averaged energy conditions and quantum inequalities (a good review here : http://arxiv.org/pdf/gr-qc/0205066.pdf). Those are of course all theoretical, though.
Here's a little list of various effects known to violate some of them. I'm not at home so I don't have all the papers in mind but I included a few :
- Squeezed quantum states, and generally various superpositions of number states for free quantum fields. Those can indeed be produced experimentally (they are commonly used because they are useful for high precision interferometry), but whether or not they violate the null energy condition remains to be proven (their energy can be made inferior to the vacuum state energy, but what the absolute energy is cannot be determined without being able to detect gravitational effects). For informations regarding them, quantum optics book usually contain a good amount of details on them. Also :
- The Casimir effect. While the Casimir effect is probably not best described by the commonly used explanation (metal plates are not perfect conductors and the Casimir is best fundamentally explained by QED loop contributions), the topological Casimir effect (where cyclical coordinates induce this) does have this explanation, and various instances of the Casimir effect (the usual one with metal plates, as well as more esoteric ones with domain walls) do seem to violate it. The same experimental problem to actually prove it applies.
- Gravitational squeezing. Various spacetimes force quantum fields into negative energy states at some points, most famously the Schartzschild metric with the Hawking radiation. Being a gravitational effect, this one cannot be tested experimentally so far.
- All manners of theories with interacting fields. Generally speaking, the most egreious violations of the energy conditions occur in interacting fields (which is the case for 2., 3. and 4.), because for the most part free fields are the main ones studied. In the case of the Casimir effect, it even violates the quantum inequalities, which is the one that is the least likely to be violated in general. Other examples in general are :
- Various cheating effects. A lot of papers also make a variety of quantum fields more or less ad-hoc to study solutions. Among those are phantom fields (fields with negative kinetic energy).
In general if you want more informations about the topic I advise "Lorentzian wormholes" by Matt Visser and "Frontiers of Propulsion Science". Don't get your hopes up too much though. The existence of exotic matter is but one problem of all spacetime trickery and the White-Juday warp field interferometer experiment is a bit suspiscious.