Synthesizing arbitrary quantum states in a superconducting resonator.

Area of Science:

• Quantum Mechanics
• Quantum Information Science
• Quantum Optics

Background:

• The superposition principle is a core concept in quantum mechanics, allowing systems to exist in multiple states simultaneously.
• Creating complex superpositions in harmonic systems is crucial for quantum computation and simulation but challenging with classical methods.

Purpose of the Study:

• To demonstrate the preparation and measurement of arbitrary quantum states in an electromagnetic resonator.
• To achieve controlled and deterministic superposition of states with varying photon numbers.

Main Methods:

• Utilized a superconducting phase qubit to coherently pump photons into a resonator.
• Employed a generalized algorithm for synthesizing photon number (Fock) states.
• Performed Wigner tomography for complete quantum state characterization.

Main Results:

• Successfully prepared and measured arbitrary quantum states in an electromagnetic resonator.
• Achieved deterministic superposition of states with different photon numbers.
• Demonstrated a method to overcome classical control limitations in harmonic systems.

Conclusions:

• This work provides a controllable method for generating complex quantum superpositions in harmonic systems.
• The demonstrated technique is a significant step towards practical quantum computation and simulation.
• Complete quantum state characterization via Wigner tomography validates the preparation method.