The Illinois Quantum and Microelectronics Park, a groundbreaking computer research development planned for the former U.S. Steel site on the city’s South Side, has lined up another major tenant. Backed by a new $25 million state grant, IBM announced plans Thursday to build the National Quantum Algorithm Center at the long-dormant South Works site, which is being redeveloped as a sprawling commercial hub to advance what has been hailed as the future of computer science. “Quantum has the potential to open a world of possibilities,” Gov.