This paper presents a breakthrough in cooling micromechanical motion to the quantum ground state using cavity opto-electro-mechanical systems. The researchers demonstrate sideband cooling of a 100 nm thick aluminum membrane, suspended 50 nm above a second aluminum layer on a sapphire substrate, to the quantum ground state. The membrane, with a diameter of 15 micrometers, is coupled to a superconducting microwave resonant circuit, enabling strong coupling between the mechanical oscillator and the microwave field. The system achieves a mechanical quality factor of 3.3 × 10^5, allowing for high-resolution measurement of mechanical motion. The team uses a Josephson parametric amplifier to measure the mechanical displacement with a sensitivity close to the Heisenberg limit. They show that the mechanical oscillator can be cooled below the thermal environment, entering the quantum regime where the mechanical motion is dominated by quantum fluctuations. The system achieves a mechanical occupancy of less than one quantum, demonstrating the ability to prepare mechanical motion in its ground state. The study highlights the potential of cavity opto-electro-mechanical systems for quantum information processing and the exploration of quantum mechanics in macroscopic systems. The device enables the coherent transfer of quantum information between different physical systems, and could be used to test quantum theory in the unexplored region of larger size and mass. The results demonstrate the ability to achieve near-quantum-limited detection of mechanical motion, with a measurement imprecision of 5.1 times the Heisenberg limit. The research opens the door to new applications in quantum mechanics, including the direct measurement of zero-point motion, observation of phonon emission and absorption asymmetry, quantum non-demolition measurements, and the generation of entangled mechanical states. The system also offers the potential for delay and storage of quantum information, as well as the transfer of quantum information between microwave and optical domains. The study represents a significant step forward in the development of quantum technologies, demonstrating the feasibility of cooling macroscopic mechanical systems to the quantum ground state.This paper presents a breakthrough in cooling micromechanical motion to the quantum ground state using cavity opto-electro-mechanical systems. The researchers demonstrate sideband cooling of a 100 nm thick aluminum membrane, suspended 50 nm above a second aluminum layer on a sapphire substrate, to the quantum ground state. The membrane, with a diameter of 15 micrometers, is coupled to a superconducting microwave resonant circuit, enabling strong coupling between the mechanical oscillator and the microwave field. The system achieves a mechanical quality factor of 3.3 × 10^5, allowing for high-resolution measurement of mechanical motion. The team uses a Josephson parametric amplifier to measure the mechanical displacement with a sensitivity close to the Heisenberg limit. They show that the mechanical oscillator can be cooled below the thermal environment, entering the quantum regime where the mechanical motion is dominated by quantum fluctuations. The system achieves a mechanical occupancy of less than one quantum, demonstrating the ability to prepare mechanical motion in its ground state. The study highlights the potential of cavity opto-electro-mechanical systems for quantum information processing and the exploration of quantum mechanics in macroscopic systems. The device enables the coherent transfer of quantum information between different physical systems, and could be used to test quantum theory in the unexplored region of larger size and mass. The results demonstrate the ability to achieve near-quantum-limited detection of mechanical motion, with a measurement imprecision of 5.1 times the Heisenberg limit. The research opens the door to new applications in quantum mechanics, including the direct measurement of zero-point motion, observation of phonon emission and absorption asymmetry, quantum non-demolition measurements, and the generation of entangled mechanical states. The system also offers the potential for delay and storage of quantum information, as well as the transfer of quantum information between microwave and optical domains. The study represents a significant step forward in the development of quantum technologies, demonstrating the feasibility of cooling macroscopic mechanical systems to the quantum ground state.