I’m a simple person. To me, a computer consists of three parts: data that goes in and out, operations that modify the data, and storage that holds the data. It is no different for quantum computing, though all three parts of the solution are still undefined: no one is exactly sure of what medium is best to represent and transport data. Different ways to encode operations are being fought over.
We're probably the furthest from having a solution when it comes to memory. But a new laser-hammer approach to storing qubits might be a step forward.
Screwdrivers for atomic physicists
In a quantum network, quantum information (or qubits) will be transported using light—single photons of light hold a qubit. But that means you also need a way to store photons, which are famous for moving very fast. One option is to store the qubit in the quantum state of a very cold gas; this works, provided you can emit the qubit as a photon later on.