The world is becoming increasingly digitalized and there is a growing need for data storage, thus increasing electricity consumption. Increased consumption is reflected in the problem of heat generation in integrated circuits. This problem has a background in transistor physics where, due to the Boltzmann distribution, transistor voltage cannot be reduced below 1V. One possible solution to this is negative electrical capacitance exhibited by ferroelectric materials. The phenomenon can be described in the framework of Landau’s theory of phase transitions, which shows that the usual solution with negative differential capacitance is unstable. Placing a layer of ferroelectric material on the dielectric below the transistor’s gate, due to boundary conditions, stabilizes the solution with negative capacitance. This gives the cumulative effect of reducing the reciprocal slope below the threshold voltage, which is about 60mV per decade in a conventional transistor. In this diploma paper, we will study the physics of ferroelectrics and describe ferroelectricity within Landau’s theory of phase transitions using the classical ferroelectric BaTiO3 as an example. Then, based on the Tsividis transistor model and the Maxwell equations, we will determine the stabilization condition and solve the obtained system using the Landau-Khalatnikov equation. We will determine the frequency-dependent dielectric response of a ferroelectric-dielectric junction in the linear regime analytically and in the non-linear regime numerically, using the programming language Mathematica.