We plan to build a modular quantum computer made of small quantum modules that, when linked, can work together to form a unified quantum state.

To determine if a quantum computer can be modular, we need to assess whether we can achieve good quality entanglements between two modules, which would prove they are part of the same quantum state.

The initial speed of our modular quantum computer will be limited by the connection rate between modules, but for small problems, the computation speed won't be a major concern.

The approach to scalability in quantum computing involves creating small, efficient quantum modules that can be linked together, rather than trying to scale up a single large quantum computer, which presents numerous challenges.

In the last three years, there's been a surge of interest from companies wanting to collaborate with academics on quantum computing research, marking a significant shift from previous years when companies were hesitant to invest.

To be genuinely useful, a quantum computer needs to exceed 50 qubits, as tasks requiring fewer qubits can still be efficiently simulated by classical computers, making them less impactful.

If you can't achieve entanglement between the Alice module and the Bob module, your quantum machine will essentially remain a collection of separate units, unable to perform a unified quantum calculation.

Microsoft is pursuing topological quantum computing, aiming to create qubits that can be controlled much better than current technologies, although it's still in the early stages of development. Scaling quantum technologies is challenging due to control engineering and other factors.

Superconducting circuits and trapped ions are currently the most advanced technologies in quantum computing, with superconducting circuits likely to lead in the next five to ten years.