Now I mainly focus on secure delegated quantum computation which is a combination of quantum cryptography and quantum computation. You see, it needs a lot of money to build and maintain quantum computers. So even if the first-generation practical quantum computers can be built in future, they are most likely to be held by governments, big companies or academics institutions. Others may need to access them in a remote way.  Then it is important to protect the privacy of users when they delegate their tasks to quantum servers.

For this question, maybe different persons have different opinions. Just to me, I tend to consider that the quantum algorithms for factorizing big integers and solving discrete logarithm problems were proposed by Peter Shor as the biggest advancement in quantum science to date. There are not good candidates now if typical classical algorithms such as RSA were broken.

It is hard to predict. If I must say, I think the next big breakthrough may be to really solve a practical problem in a certain field on a specialized quantum computer. So it needs combined efforts of researchers and engineers in various fields.

Physica Scripta mainly covers some topics in physics including quantum mechanics. Some readers or researchers who published their papers on it may have better physics background. So it can let persons who are interested in quantum science and technology to know more details about the recent developments from a physics perspective. In fact, Physcia Scripta also can support the research in this field by designing special issues on quantum science and technology for researchers of different fields and promote cross-field communication and interdisciplinary interactions.