Future space explorers and their equipment will need to easily and quickly travel from an orbiting
spacecraft to the surface of some remote planet in order to get their work done, or military personnel in
the United States need to easily and quickly travel from their military base to another remote location on
Earth in order to participate in a military operation, or space colonists will need quick transport to get
from Earth to their new home planet. Instead of using conventional transportation to expedite travel the
space explorer, military personnel or space colonist and/or their equipment go into the “Teleporter” (a.k.a.
“Transporter” in Star Trek lingo) and are “beamed down” or “beamed over” to their destinations at light
speed. The mechanism for this teleportation process is hypothetically envisioned to be the following:
1. Animate/inanimate objects placed inside the teleporter are scanned by a computer-generated and -
controlled beam.
2. The scan beam encodes the entire quantum information contained within the animate/inanimate
object(s) into organized bits of information, thus forming a digital pattern of the object(s).
3. The scan beam then dematerializes the object(s) and stores its pattern in a pattern buffer, thus
transforming the atomic constituents of the dematerialized object(s) into a matter stream.
Alternative 1: The dematerialization process converts the atoms into a beam of pure energy.
Alternative 2: The scan beam does not dematerialize the object(s).
4. The teleporter then transmits the matter/pure energy stream and quantum information signal in
the form of an annular confinement beam to its destination. Alternative: Only the quantum
information signal is transmitted.
5. At the receiving teleporter the matter/pure energy stream is sent into a pattern buffer whereby it is
recombined with its quantum information, and the object(s) is rematerialized back into its original
form. Alternative 1: The receiving teleporter recombines the transmitted quantum information
with atoms stored inside a reservoir to form a copy of the original. Alternative 2: The quantum
information is reorganized in such a way as to display the object on some three-dimensional
(holographic) visual display system.
Problem: This generic scenario is modeled after teleportation schemes found in SciFi. There are a lot of
important little details that were left out of the teleportation process because we simply do not know what
they are. This technology does not yet exist. And we are left with the question of which one of the
alternative processes identified in items 3 – 5 one wants to choose from. The above scenario is only an
outline, and it is by no means complete since it merely serves to show what speculation exists on the
subject. The above scenario describes a speculative form of what we call q-Teleportation.
There are questions to be addressed in the above scenario. Does the teleporter transmit the atoms and
the quantum bit information signal that comprises the animate/inanimate object or just the quantum bit
information signal? There are ≈ 1028 atoms of matter combined together in a complex pattern to form a
human being. How does one transmit this much information and how do we disassemble that many
atoms? Computer information gurus would insist that it is not the atoms that matter but only the bits of
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information representing them when considering the transmission of large “bodies” of information. But
are humans simply the sum of all the atoms (and the related excited atom quantum states) that comprise
them? We could possibly learn to reconstitute a beam of atoms into a chemically accurate human being.
However, would this also include the reconstruction of a person’s consciousness (personality, memories,
hopes, dreams, etc.) and soul or spirit? This question is beyond the scope of this study to address, but it is
nevertheless one of the most important concepts awaiting a complete scientific understanding.
For the teleporter to process and transmit the quantum bit information signal that encodes the
animate/inanimate object’s pattern will require stupendous digital computer power. For each atom
comprising the object we must encode its location in space (three position coordinates), its linear and
angular momentum (three vector components for each quantity), and its internal quantum state (electron
orbital-energy levels and their excitation/de-excitation and ionization states, binding to other atoms to
form molecules, molecular vibrational/rotational states, bound nuclei states, spin states for electrons and
nuclei, etc.), etc. If we assume that we can digitally encode all of this information for a single atom with
a minimum of one kilobyte (1 byte = 8 bits, 1 bit ≡ 0 or 1) of data, then we will require a minimum of
1028 kilobytes to encode and store an entire human being (in three-dimensions). To digitally store and
access this much information at present (and for the foreseeable future) is nontrivial. It will take more
than 2,400 times the present age of the universe (≈ 13 billion years) to access this amount of data using
commercially available computers (operating at ≈ 10 gigabyte/sec). Top-of-the-line supercomputers will
not reduce this time significantly. The computer technology needed to handle such a large data storage
requirement simply does not exist. The largest commercially available computers can store ≈ 40
gigabytes on a single hard drive. We will need ≈ 1020 of these hard drives to store the encoded
information of just one human being. Also, wire and coaxial/fiber optic cables do not have the physical
capacity to transmit this amount of data between devices. These numbers will not be significantly
different for macroscopic inanimate objects. The information processing and transfer technology required
for the teleportation system may become possible in 200 – 300 years if improvements in computer storage
and speed maintains a factor of 10 – 100 increase for every decade. There is speculation that emergent
molecular, bio-molecular (DNA-based systems) and quantum computer technology may achieve the
performances required for a teleportation system. In the former case molecular dynamics mimics
computer logic processes and the ≈ 1025 particles in a macroscopic sample will all act simultaneously,
making for far greater digital information processing and transfer speeds. Researchers have given no
formal performance estimates for this emergent technology. In the latter case quantum computing would
take advantage of entangled quantum states of subatomic matter or photons, whereby digital logic
processes would occur at light speed. This technology is in its infancy, and there has been no clear
direction on what performance levels will be possible in the future. This topic will be discussed further in
Section 3.2.3.
In the above teleportation scenario we might consider dematerializing animate/inanimate objects into
a matter stream consisting of only the object’s constituent atoms or atomic subcomponents (protons,
neutrons and electrons) and transmitting them at the speed of light (or close to it). To push atoms or
subatomic particles to near the speed of light will require imparting to them an energy comparable to their
rest-mass energy, which will be at a minimum of one order of magnitude larger than the amount of energy
required to break protons up into free quarks. The energy required to completely dematerialize (or
dissolve) matter into its basic quantum constituents or into pure energy is alone stupendous. At first one
will have to impart to every molecule within the object an energy that is equivalent to the binding energy
between atoms (atomic binding energy ~ chemical energy ~ several eV) in order to break apart the
molecules comprising the object’s macro-structure. After this an energy equivalent to nuclear binding
energies (≈ several × 106 times atomic binding energy, or ≈ several MeV) must be imparted to every free
atomic nucleus inside the object in order to break apart the protons and neutrons residing within each
nucleus. And last, an energy equivalent to the binding energy that holds together the three quarks
residing within each proton and neutron must be imparted to each of the free protons and neutrons within
the object. According to the Standard Model and experimental data, the quark binding energy is
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practically infinite. But all is not lost, because the Standard Model also predicts that if we could heat up
the nuclei to ≈ 1013 °C (≈ 106 times hotter than the core temperature of the Sun, or ≈ 103 MeV), then the
quarks inside would suddenly lose their binding energies and become massless (along with other
elementary matter). This heat is also equivalent to the rest-mass energy of protons and neutrons.
Therefore, to heat up and dematerialize one human being would require the annihilation of the rest massenergy
of all 1028 protons-neutrons or the energy equivalent of 330 1-megaton thermonuclear bombs.
Compare this stupendous explosive energy with the explosive yield of the largest thermonuclear bomb
ever detonated on Earth, which was a 50-megaton bomb that was built by Andrei Sakharov in the USSR
and detonated on October 30, 1961; it was called “Tzar Bomba.” Its first incarnation (ca. early October
1961) comprised a uranium fusion tamper, which gave an estimated explosive yield of ≈ 100 megatons.
But the weapon was too heavy (27 metric tons) for a bomber to carry, so the tamper was replaced by one
made of lead, which reduced both the weight and the yield. In the end we see that it is not a trivial
problem to simply heat up and dematerialize any human or inanimate objects. The technology to do so
does not exist unless we invoke new physics to get around the energy requirement.
Finally, we must consider the resolution and aperture of the optics required to scan and transmit the
animate/inanimate object’s matter (or energy) stream. The Heisenberg quantum uncertainty principle
fundamentally constrains the measurement resolution of conjugate observable quantities, such as position
and momentum or energy and time. The measurement of any combination of (conjugate) observables
with arbitrarily high precision is not possible, because a high precision measurement of one observable
leads to imprecise knowledge of the value of the conjugate observable. The quantum uncertainty
principle makes it impossible to measure the exact, total quantum state of any object with certainty. The
scan resolution of a teleportation system is defined by the wavelength of light used to illuminate the
object’s atomic/subatomic constituents and record their configurations. To resolve matter at
atomic/subatomic distance scales requires that the energy of the scanner light (photons) be extremely
large (according to the uncertainty principle); and during the scan this large light energy will be conveyed
to the constituents, causing them to drastically change their speed and direction of motion. This means
that it is physically impossible to resolve an object’s atomic/subatomic particle components and their
configurations with the precision necessary to accurately encode and later recreate the object being
teleported. To resolve atomic/subatomic particles requires wavelengths smaller than the size of these
constituents, which will typically be 1 Å – 1 fm. Such wavelengths are in the gamma ray part of the
spectrum, and this becomes a major technical problem for us because at present there is no gamma ray
electro-optics with which to work with. Now consider the example of teleporting an object from the
surface of a planet back to its spacecraft in orbit some several × 102 – 103 km away. The optical aperture
required to illuminate and scan an object with ≈ 1 Å – 1 fm resolution from orbit will be >> several × 102
– 103 km. If we are to consider teleporting an object from planet to planet or from star to star then the
aperture required will be >> several × 108 – 1013 km. These technical problems are truly insurmountable
unless totally new physics becomes available.
3.2 Quantum Teleportation
It turns out that there does in fact exist a form of teleportation that occurs in nature despite the
numerous technical roadblocks described in the previous section. It is called quantum teleportation,
which is based on the well-known concept of quantum entanglement. Erwin Schrödinger coined the word
“entanglement” in 1935 in a three-part paper (Schrödinger, 1935a, b, c, 1980). These papers were
prompted by the Einstein, Podolsky and Rosen (1935; denoted hereafter as EPR) paper that raised
fundamental questions about quantum mechanics, whereby Einstein had loudly complained that quantum
mechanics allowed physical processes resembling “spooky action at a distance” to occur. EPR
recognized that quantum theory allows certain correlations to exist between two physically distant parts of
a quantum system. Such correlations make it possible to predict the result of a measurement on one part
of a system by looking at the distant part. On this basis, EPR argued that the distant predicted quantity
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should have a definite value even before being measured, if quantum theory is complete and respects
locality (a.k.a. causality). EPR concluded that, from a classical perspective, quantum theory must be
incomplete because it disallows such definite values prior to measurement. Schrödinger’s perspective on
this argument gives the modern view of quantum mechanics, which is to say that the wavefunction (a.k.a.
quantum state vector) provides all the information there is about a quantum system. In regards to the
nature of entangled quantum states, Schrödinger (1935a, b, c, 1980) stated that, “The whole is in a
definite state, the parts taken individually are not.” This statement defines the essence of pure-state
entanglement. Schrödinger went on to give a description of quantum entanglement by introducing his
famous cat experiment.
To better understand the concept of quantum entanglement/teleportation we will focus on the
quantum wavefunction (a.k.a. quantum state function). Any quantum system such as a particle that
possesses a position in space, energy, angular and linear momentum, and spin is completely described by
a wavefunction. This is usually symbolized in a variety of ways, and we choose to represent a generic
wavefunction using the traditional “bra-ket” notation of quantum mechanics: |ϕ〉. Anything that we want
to know about the particle is mathematically encoded within |ϕ〉. As we discussed in the previous section
the wavefunction can never be completely known because there is no measurement that can determine it
completely. The only exception to this is in the special case that the wavefunction has been prepared in
some particular state or some member of a known basis group of states in advance. By measuring one of
the properties of a quantum system, we can get a glimpse of the overall quantum state that is encoded
within |ϕ〉. According to the quantum uncertainty principle the act of doing such a measurement will
destroy any ability to subsequently determine the other properties of the quantum system. So the act of
measuring a particle actually destroys some of the information about its pristine state. This makes it
impossible to copy particles and reproduce them elsewhere via quantum teleportation. However, it turns
out that one can recreate an unmeasured quantum state in another particle as long as one is prepared to
sacrifice the original particle. The trick is to exploit the EPR process to circumvent the quantum
uncertainty principle.
As discussed previously, EPR discovered that a pair of spatially separated quantum sub-systems that
are parts of an overall quantum system can be “entangled” in a non-local (i.e., non-causal) way. When
two particles come into contact with one another, they can become “entangled.” In an entangled state,
both particles remain part of the same quantum system so that whatever you do to one of them affects the
other one in a predictable fashion. More precisely, a measurement on one of the entangled sub-systems
puts it into a particular quantum state, while instantaneously putting the sub-system with which it is
entangled into a corresponding quantum state, while the two sub-systems are separated by arbitrarily large
distances in spacetime (even backwards in time!). A simple example of this phenomenon is to prepare a
pair of photons in the same quantum state such that they are entangled, and then allow them to fly apart to
remote locations without any form of communication occurring between them along their journey.
Measuring the polarization of one of the pair of entangled photons induces the other photon, which may
be light-years away, into the same state of polarization as that which was measured for its entangled twin.
The basic operation of quantum teleportation can be described as determining the total quantum state of
some large quantum system, transmitting this state information from one place to another, and making a
perfect reconstruction of the system at the new location. In principle, entangled particles can serve as
“transporters” of sorts. By introducing a third “message” particle to one of the entangled particles, one
could transfer its properties to the other one, without ever measuring those properties.
Historically, quantum entanglement was never reconciled with the quantum uncertainty principle and
the requirement of locality (or causality) in observed physical phenomena, thus it became a paradox in
quantum theory. A three-decade debate began following the appearance of the EPR paper over whether
quantum entanglement (a.k.a. “spooky action at a distance”) was a real quantum phenomenon or not, and
this debate came to be called the “EPR dilemma.” Einstein’s only solution to the dilemma was to suggest
that quantum mechanics was incomplete and needed a reformulation to incorporate local hidden-variables
that can account for observed physical phenomena without violating causality. Bell (1964) later solved
the EPR dilemma by deriving correlation inequalities that can be violated in quantum mechanics but have
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to be satisfied within every model that is local and complete. Such models are called “local hiddenvariable
models.” Bell showed that a pair of entangled particles, which were once in contact but later
moved too far apart to interact directly (i.e., causally), can exhibit individually random behavior that is
too strongly correlated to be explained by classical statistics. Bell’s inequalities make it possible to test
whether local hidden-variable models can account for observed physical phenomena in lab experiments.
Groundbreaking experimental work by Aspect et al. (1982a, b) along with further theoretical and
experimental work done by others (Freedman and Clauser, 1972; Aspect, 1983; Aspect and Grangier,
1985; Hong and Mandel, 1985; Bennett and Wiesner, 1992; Tittel et al., 1998a, b; Tittel and Weihs, 2001)
demonstrated violations of the Bell inequalities, which therefore invalidated the local hidden-variable
models. The key result of recent theoretical and experimental work is that an observed violation of a Bell
inequality demonstrates the presence of entanglement in a quantum system.
3.2.1 Description of the q-Teleportation Process
The experimental work of Bennett et al. (1993) followed by the theoretical and experimental work of
others (Vaidman, 1994; Kwiat et al., 1995; Braunstein, 1996; Braunstein and Kimble, 1998; Pan et al.,
1998; Stenholm and Bardroff, 1998; Zubairy, 1998; Vaidman and Yoran, 1999; Kwiat et al., 1999) made
the breakthrough that was necessary to demonstrate the principle of quantum teleportation in practice. It
was a remarkable technical breakthrough that settled, once and for all, the nagging question of whether
quantum entanglement could be used to implement a teleportation process to transfer information
between remotely distant quantum systems non-causally (i.e., at FTL speed). It is easy to describe how
quantum teleportation works in greater detail. Figure 6 compares conventional facsimile transmission
with the quantum teleportation process seen in Figure 7. In a conventional facsimile transmission the
original document is scanned, extracting partial information about it, but it remains more or less intact
after the scanning process. The scanned information is then sent to the receiving station, where it is
imprinted on new paper to produce an approximate copy of the original. In quantum teleportation (Figure
7) one scans out part of the information from object A (the original), which one wants to teleport, while
causing the remaining, unscanned, part of the information in A to pass, via EPR entanglement, into
another object C which has never been in contact with A. Two objects B and C are prepared and brought
into contact (i.e., entangled), and then separated. Object B is taken to the sending station, while object C
is taken to the receiving station. At the sending station object B is scanned together with the original
object A, yielding some information and totally disrupting the states of A and B. This scanned
information is sent to the receiving station, where it is used to select one of several treatments to be
applied to object C, thereby putting C into an exact replica of the former state of A. Object A itself is no
longer in its original initial state, having been completely disrupted by the scanning process. The process
just described is teleportation and not replication, and one should not confuse the two. There is a subtle,
unscannable kind of information that, unlike ordinary information or material, can be delivered via EPR
correlations/entanglement, such that it cannot by itself deliver a meaningful and controllable message.
But quantum teleportation delivers exactly that part of the information in an object that is too delicate to
be scanned out and delivered by conventional methods.
