  Visualizations have played a crucial role in helping quantum computing users
explore quantum states in various quantum computing applications. Among them,
Bloch Sphere is the widely-used visualization for showing quantum states, which
leverages angles to represent quantum amplitudes. However, it cannot support
the visualization of quantum entanglement and superposition, the two essential
properties of quantum computing. To address this issue, we propose VENUS, a
novel visualization for quantum state representation. By explicitly correlating
2D geometric shapes based on the math foundation of quantum computing
characteristics, VENUS effectively represents quantum amplitudes of both the
single qubit and two qubits for quantum entanglement. Also, we use multiple
coordinated semicircles to naturally encode probability distribution, making
the quantum superposition intuitive to analyze. We conducted two well-designed
case studies and an in-depth expert interview to evaluate the usefulness and
effectiveness of VENUS. The result shows that VENUS can effectively facilitate
the exploration of quantum states for the single qubit and two qubits.
