Quantum

Quantum (pronounced kwon-tuhm)

(1) A quantity or amount.

(2) A particular quantity or amount.

(3) A share or portion.

(4) A large quantity; something ordered, delivered or stored in bulk.

(5) In physics, the smallest quantity of some physical property, such as energy, that a system can possess according to the quantum theory; involving quanta, quantum mechanics or other aspects of quantum physics.

(6) A particle with such a unit of energy; the fundamental unit of a quantized physical magnitude, as angular momentum.

(7) Of change: (1) classically, sudden or discrete, without intermediate stages & (2) in modern adjectival use, something sudden and significant.

(8) In mathematics, a definite portion of a manifoldness, limited by a mark or by a boundary.

(9) In law, a brief document provided by the judge, elaborating on a sentencing decision (now most often used in the subcontinent); the total amount of something; the quantity.

(10) In computer operating systems, the amount of time allocated for a thread to perform its work in a multithreaded environment.

(11) In computer design, short for quantum computing.

(12) In medicine, the minimum dose of a pathogen required to cause an infection.

1610-1620: From the Late Latin quantum, noun use of the neuter form of the Classical Latin quantus (how much).

Quantum imported from Latin to physics directly by German theoretical physicist Max Planck (1858–1947) to describe the concept of the "minimum amount of a quantity which can exist".  Quantum theory is from 1912 and quantum mechanics from 1922, the latter much associated with German theoretical physicist Werner Heisenberg (1901-1976) who in 1927 deduced his "uncertainty principle" which declares an electron may have a determinate position, or a determinate velocity, but not both.  In physics, the term quantum jump (the abrupt transition from one stationary state to another) came into use in 1954 while quantum leap (sudden large advance) dates from 1963 and in figurative use (by non-physicists) describes some drastic change or radical advance in some aspect of something (and is thus often synonymous with that other favorite of post-modernists, the paradigm shift.  There are pedants (and one suspects few of them actually comprehend quantum theory) who insist “quantum leap” in the sense of “sudden & big is wrong but it’s just part of the evolution of English in its usual democratic way.  Quantum is a noun and adjective; the noun plural is quantums or quanta.

IBM quantum computer.

In an announcement little noted outside the nerd community, in late 2021 IBM introduced the Circuit Layer Operations per Second (CLOPS) performance standard for quantum computing.  As a measuring metric, CLOPS corresponds to the number of quantum circuits a quantum processing unit (QPU) can execute per unit of time, the innovation compared with previous standards such as FLOPS (Floating Point Operations per Second) and its variations (ranging from kiloFLOPS (KFlops:10³) to yottaFLOPS (YFlops: 10²⁴)), in that it expresses not only the actual speed at which the workload is processed and successfully completed but also adjusts to account for the latency of the interaction between the quantum and classical computing realms.

It must be noted that to date, the pure quantum computer has existed only in theory and that functions now executed in the quantum space involve an interaction, being mediated via a classical binary computer which translates workloads into a QPU-compatible format, retrieves the workload's results and presents them in an understandable form.  CLOPS thus accounts for not only the interval of time that the workload is actually being processed at the qubit (quantum bit) level, but also the time it takes for the system to translate and transfer information across both components.

Dating back decades, IBM has published many standards which the industry has adopted ranging from specifications for memory addressing to video displays (the famous CGA, EGA, VGA, XGA et al) and had for some time discussed the need for a harmonized standard for quantum computing.  Until CLOPS was announced, the measures had usually been expressed in terms of two of quantum’s three planes: (1) scale which pertains to the number of qubits present in any given system and (2) quality which refers to the proportion of qubits that can perform usable work expressed via quantum volume.  What CLOPS does is provide a formula to express a measure of (3) speed.

IBM has published CLOPS results for some of its quantum computing systems using machines constructed with between five and 64 qubits and it was interesting to note all had a similar quantum volume score, their actual speed (expressed in CLOPS) varied between 753 and 1419 layers per second; as IBM predicted, it was latency which accounted for the difference.  Noting that, IBM also published results from their Qiskit (Quantum Information Software Kit for Quantum Computation) project which focuses on reducing the latency in the quantum-classic computing translation layer seriously via closer physical proximity between the objects, some experiments reducing run-time cycles from 45 days to nine hours.  The company expects CLOPS to be the defined measure of quantum computing in its present form as FLOPs and its variations were to super-computing.