QC151 Quantum Physics for QC - Content moved to QC101

Explore photon polarization and its quantum behavior, revealing how polarization angles relate to qubits, through superposition, entanglement, and everyday examples like polarized sunglasses and polarizers.

Explore how vertical and horizontal polarizing filters affect photon polarization, revealing 0/1 qubit encoding and 50% transmission at 45-degree angles.

Explore how polarizing filters affect light as photons align or anti-align with the filter, showing pass-through probability from 0 to 1 based on the angle theta.

A polarizing filter changes the polarization of transmitted photons to the filter angle, here 45 degrees. Only 50% pass through, and the transmitted photons are polarized at the filter angle.

Demonstrates quantum polarizer behavior not explained by classical physics, showing a 45-degree filter between a vertical source and a horizontal polarizer that yields 25% transmission.

Explore how polarizing filters show quantum behavior for single photons, with deterministic pass-through at zero or ninety degrees and probabilistic outcomes at intermediate angles, aligning photons with the filter.

Calcite crystals split incident photons into two polarization streams, aligned and anti-aligned, showing deterministic behavior when aligned or anti-aligned and probabilistic outcomes when neither, with probabilities between 0 and 1.

Explore how a single photon's polarization becomes aligned or anti-aligned after passing through a calcite crystal, with all prior polarization information lost.

Understand the loss of information through two virtual experiments that determine the angle of polarization, via a polarizing filter and a calcite crystal, highlighting 45 degrees.

Demonstrates how a single photon’s polarization becomes a two-path outcome in calcite, destroying prior polarization information and reducing a real-valued state to a single bit.

Explore why polarization measurement yields only aligned or anti-aligned results, how measurement collapses a photon's state to a 1-bit outcome, and why a single photon's polarization angle cannot be determined.

Calcite crystals act as a measurement apparatus, altering a photon's polarization. Subsequent identical measurements yield the same result, illustrating quantum state change.

Explain how three calcite crystals aligned at the same angle measure a photon along anti-aligned paths, causing the first measurement to set anti-aligned polarization and subsequent measurements to repeat.

Demonstrate how polarizing filters at the same angle block or transmit photons; if a photon passes the first filter, its polarization aligns with the others, ensuring passage through subsequent filters.

Running two Java simulators, including a photon polarization measurement program, the lecture simulates calcite and polarizing filters; a 90-degree vertically polarized photon yields five measurements, first random, rest identical.

Explore how quantum measurement erases information and reduces a polarization angle from a number to a single bit, contrasting with classical physics where properties can be read without disturbance.

Examine the limitations of measurements in quantum physics through a 2-dimensional photon polarization simulator, revealing random outcomes and state changes for qubits as calcite angles vary.

Demonstrates why cloning a photon with unknown polarization is impossible and why measuring many clones cannot reveal the polarization angle, due to cosine-squared probability.

Explore the no-cloning theorem by contrasting cloning known polarization with the impossibility of cloning unknown quantum states; measurement yields incomplete information and irreversibly alters the system.

Measurement irreversibly loses information about the prior state, making it impossible to revert to the original state; thus measurement is an irreversible transformation in quantum physics.

Explore how photon polarization yields deterministic outcomes when aligned or anti-aligned with a polarizing filter, and probabilistic outcomes at other angles due to inherent quantum randomness that cannot be avoided.

Explore the quantum polarization simulator and observe deterministic results when cosine squared of diffAngle is 0 or 1, and analyze alignment, mean, and uncertainty across polarization angles.

Explore how photon polarization yields superposition with respect to a fixed measurement apparatus, revealing deterministic outcomes at 0 or 90 degrees and probabilistic outcomes between them, connecting to qubits.

Learn how measurement collapses superposition in quantum systems, using photon polarization at 0 or 90 degrees to illustrate qubit values and aligned versus anti-aligned outcomes.

Observe the collapse of superposition on the first measurement of a qubit; subsequent measurements with the same apparatus become deterministic and repeat the first result.

Explore two photon systems using calcite crystals, where each photon independently emerges with vertical or horizontal polarization, and joint probabilities equal the product of the individual probabilities.

Explore entanglement and how measuring one photon alters the state and outcomes of the other due to a shared state.

Explore entanglement with a Java-based simulator using four-parameter bell state to create photon pairs and observe 00 and 11 at 0.5 probability, with squares summing to 1 in 90-degree measurements.

Explore the bell state and entangled photons, showing that regardless of measurement angle, outcomes are 00 or 11 with equal probability, while rotating the apparatus changes angles but preserves correlations.

Examine how entangled photons produce 01 or 10 at 0 and 90 degrees, and how changing to 10 and 80 degrees reveals the role of measurement orientation and probabilities.

The lecture presents a photon entangled state with equal probability for 01 and 10, zero for 00 and 11, notes minus-sign, and shows simulations yielding 01 or 10 at angles.

Explore independent photons, an unentangled two-photon state, revealing equal 0/1 outcome probabilities at 75-degree measurements and that each photon's result is independent of the other's, with angle changes altering probabilities.

Run simulations of entangled photon states to show how measurement at 90 degrees reveals aligned or anti-aligned qubit values, and how measurement collapses entanglement, yielding independent results.

Explore how superposition and entanglement behave, using simulators to illustrate quantum physics without using analogies, and prepare to tackle more advanced topics in quantum computing.