Low-temperature fate of the 0.7 structure in a point contact: A Kondo-like correlated state in an open system

An overview is given on the experimental evidence that at low temperature the unpaired spin associated with the 0.7 structure forms a Kondo-like many-body state. The evidence presented includes: 1) a narrow conductance peak at zero source-drain bias that forms at low temperature, 2) collapse of conductance data onto a single function, 3) correspondence between the Kondo scaling factor and the width of the zero-bias peak, and 4) splitting of the zero-bias peak in a magnetic field.