Quantum states that exhibit superposition and entanglement serve as key resources for quantum technologies, enabling powerful computation, communication, and sensing capabilities. However, these quantum resources are notoriously fragile. Interactions with the surrounding environment—collectively referred to as dissipation—cause decoherence, eroding the delicate quantum coherence necessary for controlled quantum behavior. Conventional approaches therefore seek to minimize environmental influence through isolation or error correction to preserve coherence. Surprisingly, dissipation need not always be detrimental; under certain conditions, it can play a constructive role by stabilizing or even generating quantum coherence—an approach known as dissipative state engineering. Moreover, recent experimental developments have made it possible to achieve strong system–environment coupling in certain platforms, opening new regimes of parameter space for quantum control.

In this thesis, I apply a novel theoretical framework, the reaction-coordinate polaron-transform (RCPT) method, which enables the study of strongly coupled system–bath dynamics to examine three distinct problems. First, I study quantum spin systems, showing how tuning the bath locality can produce nontrivial magnetic order. Second, I explore fermionic chains, demonstrating that strong coupling to semi-local baths can stabilize symmetry-protected topological phases or even induce transitions from a trivial to a topological phase, with both of these initial studies focusing on the steady-state properties of systems under strong environmental interactions. Third, I analyze the relaxation dynamics of a three-level system coupled to a thermal bath, finding that strong coupling can separate relaxation into fast and slow timescales and maintain long-lived coherence—counter to the common intuition that strong coupling accelerates thermalization. Together, these results highlight how strong interactions with the environment can be leveraged as a resource to control and engineer quantum systems, offering new opportunities for both a fundamental understanding of and practical applications in quantum technology.