The paper discusses the observation of Kondo physics in a single-electron transistor (SET), which is analogous to the Kondo effect in solid-state physics. The authors fabricate a new generation of SETs using a GaAs/AlGaAs heterostructure with a 2-dimensional electron gas (2DEG) and multiple metallic gates. They measure the zero-bias conductance and differential conductance to study the Kondo phenomenon. Key findings include: 1. **Kondo Singlet Formation**: The number of electrons on the artificial atom (the droplet of electrons) affects the zero-bias conductance. For odd numbers of electrons, a spin singlet state forms, enhancing the conductance, while for even numbers, the singlet is absent. 2. **Temperature and Magnetic Field Effects**: The Kondo singlet is altered by temperature and magnetic field. At low temperatures, the peaks in the zero-bias conductance become narrower and larger, and the Kondo resonance is suppressed. A magnetic field splits the Kondo resonance into two peaks, with a splitting twice the Zeeman energy. 3. **Energy Scales**: The behavior of the SET is influenced by several energy scales, including the charging energy \( U \), the energy spacing between spatial states \( \Delta \epsilon \), and the tunneling coupling \( \Gamma \). The Kondo temperature \( T_K \) is determined by \( \Gamma \) and is comparable to accessible temperatures. 4. **Technological Implications**: The observation of Kondo physics in SETs may have technological significance, as these devices could be used in more advanced applications due to their ability to control and manipulate single electrons. The study provides a detailed experimental setup and analysis, demonstrating the robustness and potential of SETs in studying complex quantum phenomena.The paper discusses the observation of Kondo physics in a single-electron transistor (SET), which is analogous to the Kondo effect in solid-state physics. The authors fabricate a new generation of SETs using a GaAs/AlGaAs heterostructure with a 2-dimensional electron gas (2DEG) and multiple metallic gates. They measure the zero-bias conductance and differential conductance to study the Kondo phenomenon. Key findings include: 1. **Kondo Singlet Formation**: The number of electrons on the artificial atom (the droplet of electrons) affects the zero-bias conductance. For odd numbers of electrons, a spin singlet state forms, enhancing the conductance, while for even numbers, the singlet is absent. 2. **Temperature and Magnetic Field Effects**: The Kondo singlet is altered by temperature and magnetic field. At low temperatures, the peaks in the zero-bias conductance become narrower and larger, and the Kondo resonance is suppressed. A magnetic field splits the Kondo resonance into two peaks, with a splitting twice the Zeeman energy. 3. **Energy Scales**: The behavior of the SET is influenced by several energy scales, including the charging energy \( U \), the energy spacing between spatial states \( \Delta \epsilon \), and the tunneling coupling \( \Gamma \). The Kondo temperature \( T_K \) is determined by \( \Gamma \) and is comparable to accessible temperatures. 4. **Technological Implications**: The observation of Kondo physics in SETs may have technological significance, as these devices could be used in more advanced applications due to their ability to control and manipulate single electrons. The study provides a detailed experimental setup and analysis, demonstrating the robustness and potential of SETs in studying complex quantum phenomena.