IonQ jumps after successful demo of key tech, pact with South Korea's SDT

** Quantum computing company IonQ's IONQ.N shares jump nearly 11% to $45.2 premarket

** Company demonstrated an error decoder that helps in real-time correction of quantum computing errors, addressing a key challenge in keeping fragile systems reliable

** Co also announced a multiyear partnership with South Korean tech co SDT to deploy a quantum computer in South Korea; it did not disclose a deal value

** Eleven of 14 brokerages rate the stock "buy" or higher, and three "hold"; their median PT is $65 - SEG-compiled data

** Per last close, IONQ down about 9% YTD; in last 12 months, down about 43%