Physics
Double Slit Experiment
The double slit experiment is a fundamental physics experiment that demonstrates the wave-particle duality of light and matter. It involves shining a light source through two closely spaced slits onto a screen, resulting in an interference pattern characteristic of waves. This experiment has been crucial in shaping our understanding of quantum mechanics and the behavior of particles at the quantum level.
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12 Key excerpts on "Double Slit Experiment"
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 9 Double-slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). ________________________ WORLD TECHNOLOGIES ________________________ The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 4 Double-slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). ________________________ WORLD TECHNOLOGIES ________________________ The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- White Word Publications(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 9 Double-Slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Thomas Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. ________________________ WORLD TECHNOLOGIES ________________________ In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Orange Apple(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter- 10 Double-slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. ________________________ WORLD TECHNOLOGIES ________________________ In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- White Word Publications(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 5 Double-Slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in ________________________ WORLD TECHNOLOGIES ________________________ Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 18 Double-Slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Thomas Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). ________________________ WORLD TECHNOLOGIES ________________________ The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Academic Studio(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter 9 Double-Slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in ________________________ WORLD TECHNOLOGIES ________________________ Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Library Press(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter- 4 Double-slit Experiment Same double-slit assembly (0.7mm between slits); in top image, one slit is closed. Note that the single-slit diffraction pattern — the faint spots on either side of the main band — is also seen in the double-slit image, but at twice the intensity and with the addition of many smaller interference fringes. The double-slit experiment or Young's experiment involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other. In quantum mechanics the double-slit experiment demonstrates the inseparability of the wave and particle natures of light and other quantum particles (wave–particle duality). ________________________ WORLD TECHNOLOGIES ________________________ The setup used by Young, and by Newton, differs from the modern version; they passed a beam of light over a thin object such as a slip of card (in Young's case) or a hair (in Newton's case). More recently a point light source illuminates a thin plate with two parallel slits, and the light passing through the slits strikes a screen behind them. The beams emerging from the two slits are coherent, in phase, as they are derived from the same source. The wave nature of light causes the coherent light waves passing through the two slits to interfere, creating a pattern of bright and dark bands on the screen. (However, at the screen the light is always found to be absorbed as though it were composed of discrete particles, photons.) Classical particles do not interfere with each other (they can collide, but that is quite different). If classical particles are fired in a straight line through one of a pair of slits they will all strike the screen in a pattern the same size and shape as the slit; if fired through the other slit the result will be similar.
eBook - PDF- Gary N. Felder, Kenny M. Felder(Authors)
- 2022(Publication Date)
- Cambridge University Press(Publisher)
128 3 The Quantum Revolution I: From Light Waves to Photons The Double-Slit Experiment, One Particle at a Time Do you see the deep problems caused by the two different results we presented above? Remember that Young saw bright bands (lots of light) and dark bands (no light). Why is a dark band dark? It’s not because light from the left-hand slit and light from the right-hand slit are avoiding that particular region. The patch is being hit by light waves from both slits, out of phase with each other, causing destructive interference. The explanation relies on the fact that light waves spread out through space, traveling through both slits at once. On the other hand, a very dim light source creates only one dot at a time on the back wall. That result clearly points to a particle that occupies only one place at any given time. A theory is needed that coherently explains both of these results. So imagine performing the double-slit experiment one photon at a time. Active Reading Exercise: The One-at-a-Time Double-Slit Imagine the double-slit experiment with a one-photon-at-a-time light source. You fire the first photon and a dot appears at one point on Wall B. You fire a second photon, and Wall B now has two dots. Then a third and a fourth. Eventually you will have so many dots that you can plot their density on Wall B. Question: Will you see a “particle-like” pattern, with high density behind each slit and lower as you move away? Or will you see the alternating bands of high and low density that we associate with a wave? Formulate your own answer to that question. Write it down, along with a few sentences explaining your reasoning. Don’t be afraid to be wrong! But don’t just guess haphazardly either; think it through. Do not read further until you have written down your best guess. Now that you have hypothesized, here is the experimental answer: you get alternating light and dark areas! With just a few dots on Wall B, there may appear to be no pattern.
eBook - ePubQuantum Mechanics I
The Fundamentals
- S. Rajasekar, R. Velusamy(Authors)
- 2022(Publication Date)
- CRC Press(Publisher)
Essentially, the arrangement of the Double Slit Experiment appears to induce particle or wave charcter of light. To make things very clear we can consider a Mach–Zehnder interferometer experiment an equivalent experiment of the Double Slit Experiment. To test whether light priorily get the information about the experimental set up in the Double Slit Experiment John Archibald Wheeler proposed a gedanken delayed-choice experiment with the Mach–Zehnder interferometer. This thought experiment was then realized experimentally using various systems. An experiment was proposed to observe simultaneously both particle and wave character of the quantum through quantum entanglement. We discuss these developments in the present chapter.21.2 Single Slit and Double Slit Experiments
We consider the slit experiments with a beam of particles and with one particle at a time [1 ].21.2.1 Experiments With Particle
The experimental set up for the Double Slit Experiment with particle is shown schematically in Fig. 21.1 . Let a, d and L are width of a single slit, the distance separation of the two slits and the distance separation of the slits and the screen, respectively. A parallel beam of microscopic particles with constant velocity v is made to fall on a double slit.FIGURE 21.1Schematic of double slit apparatus.Suppose we first close the lower slit allowing the particles to pass only through the upper slit. Then we will get the single slit diffraction pattern at the screen. Classical diffraction theory gives the intensity of the single slit diffraction pattern as [1 , 2 ]I ( ϕ ) =(21.1)I max, ϕ =2sin ααtan− 1z L, α =,π a sin ϕλwhere ϕ is as defined in Fig. 21.1 . The intensity of the single slit diffraction pattern is shown in Fig. 21.2 . If the upper slit is closed allowing the particles to pass only through the lower slit we will again get the same diffraction pattern displaced downwards by the slit separation d. Classical theory explains successfully the diffraction pattern of a single slit.FIGURE 21.2Intensity of single slit diffraction pattern (Eq. (21.1)) for,I max= 1L = 1 m,a = 600 nmandλ = 632.8 nm
eBook - PDFQuantized Detector Networks
The Theory of Observation
- George Jaroszkiewicz(Author)
- 2017(Publication Date)
- Cambridge University Press(Publisher)
10 Double-Slit Experiments 10.1 Introduction In this chapter we show how the quantized detector network (QDN) formal- ism describes the double-slit (DS) experiment. This is arguably the simplest experiment that demonstrates quantum affects such as wave–particle duality and quantum interference. It continues to be the focus of much debate and experiment (Mardari, 2005), because theoretical modeling of what is going on reflects current understanding of quantum physics and hence physical reality. We will apply QDN to two variants: the original DS experiment and the monitored DS experiment, where an attempt is made to determine the imagined path of the particle. The DS experiment is widely acknowledged by physicists to be of importance to the understanding of quantum mechanics (QM). So much so that in 2002, the single electron version, first performed by Merli, Missiroli, and Pozzi (Merli et al., 1976), was voted by readers of Physics World to be “the most beautiful experiment in physics” (Rosa, 2012). The DS experiment can be discussed in terms of three stages, shown in Figure 10.1. By the end of the preparation stage, Σ 0 , a monochromatic beam of light or particles has been prepared by a source P , such as a laser. The beam emerges from point O and then passes through an information void V 1 to the first stage, Σ 1 , which consists of a wall or barrier W . This wall has two openings denoted A and B that allow parts of the beam to pass through into another information void V 2 and onto the second and final stage Σ 2 , which consists of a detecting screen S. The screen S is in general some material that can absorb and record particle impacts. In reality, any screen will consist of a finite number of signal detectors, such as photosensitive molecules, but the typical QM modeling is done as if there were a continuum of sites on the screen, such as C , that could register particles. 132 Double-Slit Experiments P O A E W B S C D V V z Figure 10.1.
eBook - PDF- Akira Tonomura(Author)
- 1998(Publication Date)
- World Scientific(Publisher)
Chapter 6 WAVE-PARTICLE DUALITY Up to here, when talking about electron interference phenomena, I have been taking it as a matter of course that electrons are waves. Since we have seen several kinds of interference patterns, you may have been convinced that electrons are waves like the water waves seen in Chapter 2. It also remains true, however, that electrons are particles. An electron is always a particle when detected and has never been divided into two or more pieces. You may think it is paradoxical that electrons have both wave nature and particle nature, but it is the most fundamental principle of quantum mechanics, the law of the microscopic world. Waves or Particles? The particle nature means that an electron is localized at a point, and the wave nature means that an electron is extended in a space. How can electrons have these apparently contradictory properties? The two-slit experiment demonstrating the essence of this problem is almost always introduced at the beginning of quantum mechanics textbooks. I would like to discuss this most important experiment in quantum mechanics here, though many of you may already know about it. The two-slit experiment is an interference experiment in which electrons or pho-tons are incident one by one onto two slits (Fig. 39). The time interval between them is so sparse that at most one electron or photon exists in the apparatus. The experiment using photons, in place of electrons, is described in S. Tomonaga's essay Trial of a Photon. In this essay, a prosecutor asserts that Miss Photon must have passed through one of the two slits since she has never been found split into two or more pieces. Note that a photon in Chinese characters can also be pronounced as Mitsuko, a girl's name. While she insists that the prosecutor is not right, her be-havior is inspected at the scene of the event. We send out photons one by one onto the two slits. The arrival of individual photons is recorded on the screen behind the two slits.
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