Sony traces its roots in the semiconductor business back to 1954, when it became the first Japanese company to commercialize a transistor, invented and licensed by Bell Labs; it is one of the earliest and the youngest licensee of the novel technology, together with Texas Instruments.[108][109] In 1957, Sony employee Leo Esaki and his colleagues invented a tunnel diode (usually referred to as Esaki diode) by which they discovered the quantum tunneling effect in solids, for which Esaki received the Nobel prize in Physics in 1973.[110] Sony has commanded a dominant share in the charge-coupled device market.[111]