Sample interview questions: Can you explain the concept of quantum criticality and its significance in condensed matter physics?
Sample answer:
Quantum criticality is a fundamental concept in condensed matter physics that describes the behavior of a system at its critical point, where it undergoes a phase transition driven by quantum fluctuations rather than thermal fluctuations.
In classical physics, phase transitions are typically described as occurring at a specific temperature, such as the melting of a solid or the boiling of a liquid. However, in quantum mechanics, temperature is replaced by energy, and thus phase transitions can occur at absolute zero temperature. At this point, the behavior of the system is solely determined by quantum mechanical effects.
Quantum criticality arises when a system is tuned to a critical point, often by varying a parameter such as pressure, magnetic field, or chemical composition. At this critical point, the system exhibits unique properties that are not observed under normal conditions. These properties are a consequence of the strong quantum fluctuations that dominate the behavior of the system.
One of the key features of quantum criticality is the emergence of scale-invariance, meaning that the system’s properties remain unchanged under rescaling. This scale invariance is associated with a phenomenon known as a quantum phase transition, where the system undergoes a sudden change in its ground state as the tuning parameter passes through the critical value.
Quantum criticality has significant implications in condensed matter physics. It allows us to understand and predict the behavior of a wide range of mater… Read full answer
Source: https://hireabo.com/job/5_0_7/Condensed%20Matter%20Physicist