How Quantum Computers differ from classical computers?

The difference between a classical computer and a quantum computer is not as simple as an old car and a new car. Rather, it’s like the difference between a car and a aeroplane, while one can run, the  other  can  fly. Conventional  computers  are  strictly  digital, and rely purely on classical computing principles and properties.

Quantum  computers  are  strictly quantum,  they  rely  on quantum principles  and  properties  —  most  importantly  superposition(they can be in two states at once) and entanglement.

Working of Quantum Computing 

Quantum  computers  use  quanta  as  a  physical  system  which  allows information  to  be  carried  out  in  both  0  and  1  state simultaneously. Whereas  in  classic  computing  information  is carried  in  either  0  or 1  bit.  Quantum  computing  increase  the speed of the system exponentially as it can hold more information as compare to classical computers. Suppose  there  are  equal  number  of  quanta  bits  and  regular  bits, then the quanta bit will hold twice the information i.e lets say there are n quanta bits in the supercomputer, then it will have 2^n  different states. Therefore  quantum  computing  can  hold  more information thereby increase in the speed of system.

In  theory  quantum  computing  seems  mind blowing  but  at  the  same time  it  is  difficult  to  build.  The  qubits  are  dynamic  so  the accurate measurement is difficult and requires complex algorithms.

Why Quantum Computing?

• Classical  Bits: If there  are  n  quanta bits  in  the supercomputer,  then  it  will  have  2^n  different  states. Therefore quantum computing can hold more information thereby increase in the speed of system.

•Qubits: A qubit  is  the  physical  carrier  of  quantum information.  Qubit  can  take  values  of  0’s,  1’s,  or  both  at same  time.  Classical  computes  encode  information  in  bits whereas  quantum  computers  use  qubits.  An  each  qubit  can represent  both  a  1  and  a  0  at  the  same  time.  Using  qubit, Quantum  Computers  can  hold  more  information  than  classical computers and solve problems faster and more efficiently.

•Superposition: Each qubit  represent  0’s  ,1’s  or  both  at once.

•Entanglement: When  connection  between  two  qubits  in  a superposition  is  correlate  with  each  other,  state  of  one depends on the state of another.

Conclusion

Classical  computers  are  deterministic  computers.  Their  basic states are deterministic in nature whereas quantum computers will be probabilistic  computers.  Their  basic  states  will  be probabilistic   in  nature.  Quantum  computers  is  faster  in  solving mathematical   tasks  using  various  algorithms  than  classical computers.  Quantum systems  cannot  be  done  all  correctly  on  a classical  computer. This  task will  be  handled  correctly  on  a quantum computer.