Quiz: Quantum 101

Quantum computers have the potential to outperform classical computers for certain types of problems, such as:

• Sending emails and browsing the internet.

• Running word processing software.

• Simulating quantum systems and factoring large numbers.

• Playing video games.

Answer explanation

Quantum computers excel at tasks like simulating quantum systems and factoring large numbers due to their ability to process complex calculations simultaneously, unlike classical computers which struggle with these specific problems.

In the double-slit experiment with electrons, even when sent one at a time, they still create an interference pattern. This suggests that:

• Electrons are larger than the slits.

• Electrons can be in multiple places at once.

• Electrons always travel in straight lines.

• The experimental setup is flawed.

Answer explanation

The interference pattern indicates that electrons exhibit wave-like behavior, allowing them to be in multiple places at once, which is a fundamental principle of quantum mechanics.

What term describes the smallest indivisible unit of energy?

• Electron

• Photon

• Quantum

• Wave packet

Answer explanation

The term 'quantum' refers to the smallest indivisible unit of energy, representing discrete packets of energy in quantum mechanics. While photons are energy carriers, 'quantum' is the broader term for energy units.

What is a qubit in the context of quantum computing?

• A classical bit that can store more information.

• A quantum bit that can exist in a superposition of 0 and 1.

• A fundamental particle used in quantum processors.

• A unit of quantum entanglement.

Answer explanation

A qubit is a quantum bit that can represent both 0 and 1 simultaneously due to superposition, unlike a classical bit which can only be in one state at a time. This property is fundamental to quantum computing.

Quantum probability waves are described by a mathematical function called the:

• Fourier transform

• Gaussian distribution

• Wavefunction

• Laplacian operator

Answer explanation

Quantum probability waves are represented by the wavefunction, which encodes the probabilities of finding a particle in various states. The wavefunction is fundamental in quantum mechanics, unlike the other options listed.

Quantum field theory describes fundamental particles as:

• Tiny billiard balls with specific properties.

• Vibrations or excitations of underlying quantum fields.

• Knots in the fabric of spacetime.

• Higher-dimensional objects projected into our 3D world.

Answer explanation

Quantum field theory posits that fundamental particles are not just tiny objects but rather vibrations or excitations of quantum fields that permeate space, making this choice the most accurate representation.

Heisenberg's uncertainty principle states that there is a fundamental limit to the precision with which we can simultaneously know certain pairs of physical properties of a particle, such as:

• Mass and energy

• Charge and spin

• Position and momentum

• Temperature and pressure

Answer explanation

Heisenberg's uncertainty principle specifically addresses the limits of measuring position and momentum simultaneously. This means that the more accurately we know one, the less accurately we can know the other.

If two entangled particles are measured, and one is found to have spin "up," what can be instantly known about the spin of the other particle (assuming they were initially in a singlet state)?

• It will also be spin "up."

• It will be spin "down."

• Its spin will be randomly determined at the moment of measurement.

• Nothing can be known about the other particle's spin.

Answer explanation

In a singlet state, the spins of two entangled particles are opposite. If one particle is measured and found to have spin 'up', the other must be spin 'down' to conserve total spin, making 'It will be spin "down."' the correct answer.

The famous double-slit experiment demonstrates which fundamental concept of quantum mechanics?

• The photoelectric effect

• Wave-particle duality

• Quantum entanglement

• Radioactive decay

Answer explanation

The double-slit experiment illustrates wave-particle duality by showing that particles like electrons can exhibit both wave-like and particle-like behavior, depending on whether they are observed.

Which of the following is a major challenge in building practical quantum computers?

• Making transistors smaller.

• Maintaining the coherence of qubits.

• Increasing the speed of light.

• Finding enough silicon.

Answer explanation

Maintaining the coherence of qubits is crucial for quantum computers, as qubits must remain in a superposition state long enough to perform calculations. Other options do not address the fundamental challenges of quantum computing.