With not just one, but two complete formulations of quantum mechanics in hand, the quantum theory grew explosively. It was applied to the atoms, molecules and solids. It solved with ease the problem of helium that had defeated the old quantum theory. It resolved problems concerning the structure of stars, the nature of superconductors, and the properties of magnets. One particularly important contributor was Dirac, who in 1926 (at age 22) extended the theory to relativistic and field-theoretic situations. Another was Linus Pauling, who in 1931 (at age 30) developed quantum mechanical ideas to explain chemical bonding, which previously had been understood only on empirical grounds.Research that employs quantum mechanics remains at the center of contemporary physics. We shall touch on two areas:

Quantum gravity
Although there are no observations "yet" that require the use of quantum theory of gravity, there are several attempts to include gravity among the phenomena that can be described by quantum mechanics. Why? If classical mechanics (Newtonian and general relativity laws) descibe the gravity pretty well, why do we need to resort to quantum theory? The reason is that physicists believe that way back at the earliest moment of the creation of the universe (less than 10^-43 seconds after the big bang), gravity was indeed a quantum phenomena. Notice that at time there was no atoms. The first atom was formed 3 minutes after the creation!
So you see quantum mechanics is not as modern as you might think.

Cosmological quantum mechanics
A new trend in quantum mechanics was introduced to solve the basic flaw of measurements in Copenhagen Interpretation of the world. This trend is looking at the whole universe as a quantum system, treated as one system. As you might recall, the flaw of measurements in Copenhagen Interpretation is that the measuring device (a quantum system itself), is considered "outside" the physical system to be measured. However, according to the new cosmological quantum physicists, there is nothing outside the universe, which could affect the measuring process of any physical system.