Page 37 - Undergraduate Research Opportunities Program Proceedings 2017-18

School of Science
Department of Physics

Department of Physics

No-collapse Quantum Mechanics
Supervisor: CHEN Tian Wen / PHYS
Student: FONG Kai Yuan / PHYS Course: UROP1100, Summer

Since its inception in the early 20th century, Quantum Mechanics has been a successful theory in giving accurate and
consistent predictions to the behavior of particles at the atomic scale. However, there are two main questions that still
have not been answered: why do wavefunctions collapse in a non-unitary fashion and why the probability of measured
value is the square of the amplitude, viz., the Born rule? In this research, we studied two proposed solutions to these
two problems: decoherence and Many World Interpretation. We investigated the weaknesses of each solution. The
topic of subjective probability used to derive Born rule in the Many Worlds Interpretation was also discussed briefly.

Supervisor: CHEN Tian Wen / PHYS
Student: FUNG Sze Ching / PHYS Course: UROP1100, Fall

The probabilistic nature of quantum mechanics has been a longstanding problem. It was proposed by Everett that the
probabilistic feature of quantum mechanics is indeed due to the ignorance of observers, and in a more global view, the
wavefunciton, together with the observer, branching into all possible outcomes. As a result, the wavefunction looks
probabilistic to an observer in a particular branch of the wavefunction. In this interpretation, the probability is
interpreted as the ”Self-locating Uncertainty” of an observer, but at the same time reducing to Born’s Rule when an
observer in a particular branch tries to measure such a probability.

Supervisor: CHEN Tian Wen / PHYS
Student: MA Junwei / PHYS-IRE Course: UROP1100, Summer
In this report, we’ll first examine two proofs of Born rule in Many Worlds Interpretation of quantum mechanics (MWI):
Decision theoretic approach by Deutsch and Wallace, and Envariance approach by Zurek. Then we will further
contemplate on the Hilbert space framework, which will lead to an interpretation of Gleason’s theorem. Then, doubts
on the validity of Hilbert space itself will further take us to the investigation of quantum logic, where the origin of
quantum probability is likely located. The final part is the author’s own opinion about the interpretation of quantum
probability, that we’d better treat it as a part of quantum logic instead of postulating various interpretations on it.

Optical Microscopy
Supervisor: DU Shengwang / PHYS Co-Supervisor: CHEN Sherry / MAE
Student: CHIU Hoi Chun / PHYS-IRE Course: UROP1100, Fall
UROP2100, Spring
UROP3100, Summer

In this UROP project series, we would like to build a differential interference contrast microscope (DIC) to quantitatively
reconstruct alloy surfaces and study phase transformation. Following the concept and design of the system proposed
previously in UROP 1100 and UROP 2100, we now work on the software to control various hardware and make sure the
data from the camera flow to the computer properly. In the following, the structure of the software and the data flow
will be discussed.

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