@381dbcc7: In quantum computing, a quantum gate is a basic building block used to manipulate quantum bits (qubits). When a quantum gate is "open," it means that it is not being used to perform any specific operation on the qubits.
However, in the context of quantum mechanics, the term "quantum gate" is not commonly used. Instead, the term "quantum state" is used to describe the state of a quantum system. In this context, leaving a quantum system "open" could mean that it is not being measured or observed, and is therefore allowed to evolve according to the laws of quantum mechanics.